Jewellery bars and jewellery

Abstract

The jewelry bullion comprises a first phase, a second phase, and a third phase, each containing gold as a major component. The first phase, the second phase, and the third phase are not intermixed with one another. The first phase contains palladium as a minor component. The second phase contains copper and silver as minor components. The third phase contains copper and silver as minor components. The copper content in the second phase is higher than the copper content in the third phase. The silver content in the third phase is higher than the silver content in the second phase.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to jewelry bullion and jewelry. [Background technology]

[0002] It is known that bullion containing precious metals is used for watch parts (see, for example, Patent Document 1 below). The bullion described in Patent Document 1 is sometimes referred to as a bullion for watch parts. The bullion for watch parts described in Patent Document 1 contains a first precious metal and a second precious metal. The first precious metal and the second precious metal are distributed in a state where they are distinguished from each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2023 / 242751 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for jewelry bullion that can give users a variety of aesthetic sense. Note that jewelry bullion also includes bullion for wristwatches.

[0005] An object of the present disclosure is to provide jewelry bullion and jewelry that can give users a variety of aesthetic sensations. [Means for solving the problem]

[0006] A jewelry bullion according to the present disclosure comprises a first phase, a second phase, and a third phase containing gold as a major component. The first phase, the second phase, and the third phase are not intermixed with one another. The first phase contains palladium as a minor component. The second phase contains copper and silver as minor components. The third phase contains copper and silver as minor components. The copper content in the second phase is higher than the copper content in the third phase. The silver content in the third phase is higher than the silver content in the second phase. [Effects of the Invention]

[0007] Jewelry bullion and jewelry according to the present disclosure can provide a variety of aesthetic sensations to the user. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 shows a processed secondary electron image of the jewelry bullion of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements. [Figure 2] FIG. 2 shows a secondary electron image of the jewelry bullion of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements. [Figure 3] Figure 3 shows an example where the jewellery item is a ring. [Figure 4] FIG. 4 shows a processed secondary electron image of the jewelry bullion of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements. [Figure 5] FIG. 5 shows a secondary electron image of the jewelry bullion of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements. [Figure 6] FIG. 6 shows a processed secondary electron image of the jewelry bullion of Example 3 and an intensity distribution image of characteristic X-rays derived from metal elements. [Figure 7] FIG. 7 shows a secondary electron image of the jewelry bullion of Example 3 and an intensity distribution image of characteristic X-rays derived from metal elements. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Outline of the embodiment] A jewelry bullion according to the present disclosure comprises a first phase, a second phase, and a third phase containing gold as a major component. The first phase, the second phase, and the third phase are not intermixed with one another. The first phase contains palladium as a minor component. The second phase contains copper and silver as minor components. The third phase contains copper and silver as minor components. The copper content in the second phase is higher than the copper content in the third phase. The silver content in the third phase is higher than the silver content in the second phase.

[0010] In this jewelry bullion, the compositions of the minor components of the first, second, and third phases are different from one another, and the first, second, and third phases do not intermix with one another, so the first, second, and third phases can each exhibit different colors. Therefore, the jewelry bullion can provide users with a variety of aesthetic sensations. For example, the jewelry bullion can provide users with a three-color camouflage pattern.

[0011] In the jewelry bullion, the average size of each of the first, second, and third phases may be 0.2 mm or more and 2.0 mm or less. If the average size of each of the first, second, and third phases is 0.2 mm or more, the first, second, and third phases can be recognized by the user with the naked eye, and diverse aesthetic impressions based on the different colors of the first, second, and third phases can be perceived. If the average size of each of the first, second, and third phases is 2.0 mm or less, the user can perceive excellent aesthetic impressions.

[0012] The jewelry bullion may further include a fourth phase that is immiscible with the first, second, and third phases. The fourth phase does not contain gold and contains platinum as a main component. In the jewelry bullion, the fourth phase exhibits a color different from the first, second, and third phases that contain gold. This allows the jewelry bullion to provide users with a wider variety of aesthetic appeal. For example, the jewelry bullion can provide users with a four-color camouflage pattern.

[0013] In the jewelry bullion, the fourth phase may have an average size of 0.2 mm or more and 2.0 mm or less. If the average size of the fourth phase is 0.2 mm or more, the fourth phase can be recognized by the user with the naked eye, and various aesthetic impressions based on the color of the fourth phase can be perceived. If the average size of the fourth phase is 2.0 mm or less, the user can be perceived as having excellent aesthetics.

[0014] In the jewelry bullion, the first phase may further contain platinum as a minor component. The platinum content in the fourth phase is higher than the platinum content in the first phase. A jewelry bullion in which the first phase further contains platinum as a minor component is suitable for jewelry.

[0015] The material of the jewelry according to the present disclosure is the above-mentioned jewelry bullion. This jewelry can give a variety of aesthetic sensations to the user.

[0016] [Specific example of embodiment]

[0017] [First embodiment] A first embodiment as a specific example of an embodiment of a jewelry bullion and a piece of jewelry will be described with reference to Figures 1 to 3. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0018] FIG. 1 shows a processed secondary electron image of the jewelry bullion of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements. FIG. 2 shows a processed secondary electron image of the jewelry bullion of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements. FIG. 2A is a secondary electron image. FIG. 2B is an intensity distribution image of characteristic X-rays derived from silver (Ag). FIG. 2C is an intensity distribution image of characteristic X-rays derived from copper (Cu). FIG. 2D is an intensity distribution image of characteristic X-rays derived from platinum (Pt). FIG. 2E is an intensity distribution image of characteristic X-rays derived from palladium (Pd). FIG. 2F is an intensity distribution image of characteristic X-rays derived from gold (Au). In each of FIGS. 1A to 1F, a process has been performed to draw boundaries between the phases of FIGS. 2A to 2F. FIG. 3 shows an example in which the jewelry is a ring.

[0019] [Basic composition of jewelry bullion 1] The outer shape of the jewelry metal 1 is not limited. The jewelry metal 1 preferably does not contain voids inside. As shown in FIGS. 1 and 2, the jewelry metal 1 comprises a first phase 2, a second phase 3, and a third phase 4. In this embodiment, the jewelry metal 1 comprises only the first phase 2, the second phase 3, and the third phase 4, and does not comprise any other phases. The third phase 4 fills the gaps between the first phase 2, the gaps between the second phase 3, and the gaps between the first phase 2 and the second phase 3. The first phase 2, the second phase 3, and the third phase 4 do not intermix with each other. In other words, the first phase 2, the second phase 3, and the third phase 4 are incompatible with each other. The first phase 2, the second phase 3, and the third phase 4 are independent of each other and are phase-separated. The boundary between the first phase 2 and the second phase 3, the boundary between the second phase 3 and the third phase 4, and the boundary between the first phase 2 and the third phase 4 are all observed in the intensity distribution image of characteristic X-rays. That is, the first phase 2, the second phase 3, and the third phase 4 are each confirmed (identified) by the color difference of each phase as seen in the intensity distribution image of characteristic X-rays or under a microscope.

[0020] [Major components in Phase 1 2, Phase 2 3, and Phase 3 4] As shown in FIGS. 1F and 2F, each of the first phase 2, the second phase 3, and the third phase 4 contains gold as a main component. Each of the first phase 2, the second phase 3, and the third phase 4 is made of a gold alloy. The gold content in each of the first phase 2, the second phase 3, and the third phase 4 is 70 mass % or more and 80 mass % or less. The gold content is calculated based on the intensity of gold in a characteristic X-ray intensity distribution image.

[0021] [Secondary ingredients and additional ingredients in Phase 1 2] As shown in Figures 1E and 2E, the first phase 2 contains palladium as a minor component. In Figure 2E, the lighter (whiter) the color in the characteristic X-ray intensity distribution image, the higher the palladium content. Therefore, in the jewelry bullion 1, the palladium content in the slightly white first phase 2 is higher than the palladium content in the second phase 3 and third phase 4, which are darker than the first phase 2. Note that the relationship between the whiteness of the characteristic X-ray intensity distribution image in each of Figures 1A to 1D and the respective contents of silver, copper, and platinum is the same as that for palladium described above. The palladium content in the first phase 2 is 5% by mass or more, and may be 10% by mass or more, or 20% by mass or less, or 15% by mass or less. The palladium content is calculated based on the intensity of palladium in the characteristic X-ray intensity distribution image.

[0022] In this embodiment, as shown in FIGS. 1D and 2D, the first phase 2 further contains platinum as a minor component. The platinum content in the first phase 2 is 5% by mass or more and 15% by mass or less, and may be 10% by mass or less. The platinum content is calculated based on the intensity of platinum in a characteristic X-ray intensity distribution image. The minor component content in the first phase 2 is 5% by mass or more and 15% by mass or less.

[0023] In addition to the main component and the subcomponent, the first phase 2 may further contain a first additive component. The first additive component may be at least one selected from the group consisting of copper (see FIGS. 1C and 2C), silver, and zinc. The content of the first additive component in the first phase 2 is lower than the content of the subcomponent in the first phase 2. The content of the first additive component in the first phase 2 may be 10% by mass or less, or may be 5% by mass or less. In addition to the main component, the subcomponent, and the first additive component, the first phase 2 may contain unavoidable impurities. The unavoidable impurities are impurities that are unavoidably (unintentionally) mixed into the first phase 2 during the production of the jewelry bullion 1. The content of the unavoidable impurities in the first phase 2 may be 0.1% by mass or less, or may be 0.05% by mass or less. The first phase 2 is derived from particles of a white gold alloy (described below), and is therefore sometimes referred to as a white gold alloy phase.

[0024] [Subsidiary and additional ingredients in Phase 23 and Phase 34] As shown in FIGS. 1B and 1C, the second phase 3 contains copper and silver as minor components. The third phase 4 contains copper and silver as minor components. As shown in FIG. 2C, the copper content in the second phase 3 is higher than the copper content in the third phase 4. The copper content in the second phase 3 is 13% by mass or more, and may be 15% by mass or more, or 25% by mass or less, or 20% by mass or less. The copper content in the third phase 4 is higher than the copper content in the first phase 2 (first additive component). The copper content in the third phase 4 is 12% by mass or less, and may be 10% by mass or less, or 3% by mass or more, or 5% by mass or more. The value obtained by subtracting the copper content in the third phase 4 from the copper content in the second phase 3 is 3% by mass or more, or 20% by mass or less. The ratio of the copper content in the second phase 3 to the copper content in the third phase 4 is not less than 1.5 and not more than 4. The copper content is calculated based on the copper intensity in a characteristic X-ray intensity distribution image.

[0025] In addition to the main and subcomponents, the second phase 3 may further contain a second additive component. An example of the second additive component is palladium. As shown in FIGS. 1E and 2E, the palladium content in the second phase 3 is lower than the palladium content in the first phase 2. The palladium content in the second phase 3 is 4% by mass or less, and may be 3% by mass or less. The ratio of the palladium content in the first phase 2 to the palladium content in the second phase 3 is 2 to 10.

[0026] As shown in FIG. 2B , the silver content in the third phase 4 is higher than the silver content in the second phase 3. The silver content in the third phase 4 is 13% by mass or more, and may be 15% by mass or more, or 25% by mass or less, or 20% by mass or less. The value obtained by subtracting the silver content in the second phase 3 from the silver content in the third phase 4 is 3% by mass or more and 20% by mass or less. The ratio of the silver content in the third phase 4 to the silver content in the second phase 3 is 1.5 or more and 4 or less. The silver content is calculated based on the intensity of silver in a characteristic X-ray intensity distribution image. The third phase 4 may further contain a third additive component in addition to the main component and the subcomponent. The type and content of the third additive component are the same as those of the second additive component described above.

[0027] The second phase 3 may contain inevitable impurities in addition to the main component, the minor component, and the second additional component. The third phase 4 may contain inevitable impurities in addition to the main component, the minor component, and the third additional component. The inevitable impurities are impurities that are inevitably (unintentionally) mixed into the second phase 3 and the third phase 4 during the production of the jewelry bullion 1. The content of the inevitable impurities in each of the second phase 3 and the third phase 4 is 0.1% by mass or less, and may be 0.05% by mass or less. The second phase 3 is sometimes referred to as a pink gold alloy phase because it is a phase derived from particles made of a pink gold alloy (described below). The third phase 4 is sometimes referred to as a yellow gold alloy phase because it is a phase derived from particles made of a yellow gold alloy (described below).

[0028] The average size of each of the first phase 2, the second phase 3, and the third phase 4 is 0.2 mm or more, preferably 0.5 mm or more, and 2.0 mm or less, preferably 1.5 mm or less. The average sizes of the first phase 2, the second phase 3, and the third phase 4 are determined by observation using a digital microscope.

[0029] The volume proportions of the first phase 2, the second phase 3, and the third phase 4 in the jewelry metal 1 may be the same or different from one another and are 25 volume % or more, or 30 volume % or more, or 40 volume % or less, or 35 volume % or less. The volume proportions of the first phase 2, the second phase 3, and the third phase 4 are determined by observation using a digital microscope.

[0030] [Method for manufacturing jewelry bullion 1 and jewelry 10] [Preparation of the first to third lines] First, a first wire made of a first gold alloy, a second wire made of a second gold alloy, and a third wire made of a third gold alloy are prepared.

[0031] The first gold alloy may be a white gold alloy. The white gold alloy contains a primary component, a secondary component, and a first additional component contained in a first phase 2. The second gold alloy may be a pink gold alloy. The pink gold alloy contains a primary component, a secondary component, and a second additional component contained in a second phase 3. The third gold alloy may be a yellow gold alloy. The yellow gold alloy contains a primary component, a secondary component, and a third additional component contained in a third phase 4. The cross section perpendicular to the longitudinal direction of each of the first, second, and third wires may be circular or rectangular (square). When the cross section is circular, the diameter of each of the first, second, and third wires is 0.4 mm or more and 1.0 mm or less.

[0032] Next, each of the first, second, and third wires is cut at equal intervals in the longitudinal direction. The intervals are 0.2 mm or more, optionally 0.3 mm or more, and 1.0 mm or less, optionally 0.5 mm or less. By cutting each of the first, second, and third wires, first gold alloy particles, which are particles made of the first gold alloy, second gold alloy particles, which are particles made of the second gold alloy, and third gold alloy particles, which are particles made of the third gold alloy, are prepared, respectively. The median particle diameter of each of the first gold alloy particles, second gold alloy particles, and third gold alloy particles is 0.2 mm or more, preferably 0.4 mm or more, and 1.0 mm or less, preferably 0.5 mm or less. Hereinafter, the first gold alloy particles may be referred to as white gold alloy particles. The second gold alloy particles may be referred to as pink gold alloy particles. The third gold alloy particles may be referred to as yellow gold alloy particles. The first gold alloy particles, the second gold alloy particles, and the third gold alloy particles may be collectively referred to simply as gold alloy particles.

[0033] Next, gold alloy particles and gold particles are blended. The median particle diameter of the gold particles is 1 μm or more and 100 μm or less. The gold particles are blended with the gold alloy particles to fill the gaps between the gold alloy particles. Preferably, gold particles with good adhesiveness to the gold alloy particles are blended for gap filling. The ratio of the median particle diameter of the gold particles to the median particle diameter of the gold alloy particles is 0.5 or less, preferably 0.1 or less, and also 0.001 or more. The blending ratio of the first gold alloy particles in the gold alloy particles is 30% by mass or more and 45% by mass or less. The blending ratio of the second gold alloy particles in the gold alloy particles is 25% by mass or more and 40% by mass or less. The blending ratio of the third gold alloy particles in the gold alloy particles is 25% by mass or more and 40% by mass or less. The blending ratio of the gold alloy particles to the total of the gold alloy particles and the gold particles is 90% by mass or more and 99% by mass or less. The gold particles are made of gold. The blending ratio of the gold particles to the total of the gold alloy particles and gold particles is 1% by mass or more and 10% by mass or less. The gold alloy particles and gold particles are mixed in the above ratio to prepare a mixture.

[0034] The mixture is then subjected to spark plasma sintering (SPS). Compared to other conventional sintering methods (e.g., atmospheric sintering), SPS can reliably produce a jewelry base metal 1 with a high density and a jewelry base metal 1 having a first phase 2, a second phase 3, and a third phase 4 that do not intermix with one another. In SPS, a mold having a cavity therein is used. The mold is configured so that an object to be placed in the cavity can be pressurized. The mixture is then placed in the cavity, and a voltage is then applied while the mold and mixture are pressurized. This heats the mold and mixture. In SPS, the pressure on the mixture is 10 MPa or more and 100 MPa or less, the sintering temperature is 600°C or more and 800°C or less, and the sintering time (holding time) is 1 minute or more and 10 minutes or less. SPS forms a first phase 2, a second phase 3, and a third phase 4 corresponding to the first gold alloy particles, the second gold alloy particles, and the third gold alloy particles, respectively, and gold diffuses (migrates) into each of the first phase 2, the second phase 3, and the third phase 4. Furthermore, SPS causes a plurality (2 to 5) of first gold alloy particles to aggregate to form the first phase 2. SPS also causes a plurality (2 to 5) of second gold alloy particles to aggregate to form the second phase 3. SPS also causes a plurality (2 to 5) of third gold alloy particles to aggregate to form the third phase 4. Jewelry bullion 1 is thus produced.

[0035] For small jewelry (e.g., rings), phases with small sizes are desired. In the method for producing jewelry bullion described in Patent Document 1, powders of a first precious metal and a second precious metal are produced using an atomizer and then sintered. These powders each have a particle size distribution. With the production method described in Patent Document 1, because the powders have a particle size distribution, it is difficult to produce jewelry bullion having phases with sizes that are as small as possible within the visible range. Considering production costs, it is also difficult to sieve the powder. On the other hand, it is also difficult to produce powders with large sizes using an atomizer. However, with the production method disclosed above, it is possible to produce jewelry bullion 1 having phases with desired sizes.

[0036] The shape of the jewelry bullion 1 is not limited. The jewelry bullion 1 is shaped to produce jewelry 10, as shown in FIG. 3 . The jewelry bullion 1 is used as the material for the jewelry 10. In other words, the material for the jewelry 10 is the jewelry bullion 1. Shaping processes include cutting and polishing. The jewelry 10 includes, but is not limited to, rings, earrings, necklaces, bracelets, pendants, chains, bangles, brooches, anklets, tiaras, cufflinks, hairpins, and obi clasps. FIG. 3 shows an example in which the jewelry 10 is a ring 11. The ring 11 includes an outer peripheral surface 12, an inner peripheral surface 13, and two end surfaces 14. The inner peripheral surface 13 is located inside the outer peripheral surface 12. Each of the two end surfaces 14 connects the outer peripheral surface 12 and the inner peripheral surface 13. When the ring 11 is not worn by the user, the user can see a three-color pattern (for example, a three-color camouflage pattern) based on the first phase 2, the second phase 3, and the third phase 4 on the outer peripheral surface 12, the inner peripheral surface 13, and the two end surfaces 14. When the ring 11 is worn by the user, the user can see the above-mentioned three-color pattern on the outer peripheral surface 12 and the two end surfaces 14.

[0037] [Modification of the first embodiment] Although not shown, in this modification, the first phase 2 (see FIGS. 1D and 2D) does not contain platinum as a secondary component. That is, the first phase 2 (see FIGS. 1E and 2E) does not contain platinum, and the secondary component is only palladium.

[0038] [Second embodiment] A second embodiment as a specific example of an embodiment of a jewelry bullion will be described with reference to Figures 4 and 5. Figure 4 is a processed secondary electron image of the jewelry bullion of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements. Figure 5 is a processed secondary electron image of the jewelry bullion of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements. Figure 5A is a secondary electron image. Figure 5B is an intensity distribution image of characteristic X-rays derived from silver (Ag). Figure 5C is an intensity distribution image of characteristic X-rays derived from copper (Cu). Figure 5D is an intensity distribution image of characteristic X-rays derived from platinum (Pt). Figure 5E is an intensity distribution image of characteristic X-rays derived from palladium (Pd). Figure 5F is an intensity distribution image of characteristic X-rays derived from gold (Au). In each of Figures 4A to 4F, a process has been performed to draw boundaries between the phases of Figures 5A to 5F.

[0039] [Phase 4 5] 4A, the jewelry metal 1 further includes a fourth phase 5. That is, the jewelry metal 1 includes a first phase 2, a second phase 3, a third phase 4, and a fourth phase 5.

[0040] In this embodiment, the jewelry metal 1 includes only the first phase 2, the second phase 3, the third phase 4, and the fourth phase 5, and does not include any other phases. The fourth phase 5 is not mixed with each of the first phase 2, the second phase 3, and the third phase 4. In other words, the fourth phase 5 is incompatible with each of the first phase 2, the second phase 3, and the third phase 4. That is, the fourth phase 5 is independent from each of the first phase 2, the second phase 3, and the third phase 4, and is phase-separated from each of the first phase 2, the second phase 3, and the third phase 4. The fourth phase 5 fills gaps between the first phase 2, the second phase 3, the third phase 4, the gaps between the first phase 2 and the second phase 3, the gaps between the second phase 3 and the third phase 4, and the gaps between the first phase 2 and the third phase 4. The boundary between the first phase 2 and the fourth phase 5, the boundary between the second phase 3 and the fourth phase 5, and the boundary between the third phase 4 and the fourth phase 5 are all observed in the intensity distribution image of characteristic X-rays. The fourth phase 5 is confirmed (identified) in the intensity distribution image of characteristic X-rays.

[0041] As shown in FIGS. 4D and 5D, the fourth phase 5 contains platinum as a main component. The platinum content in the fourth phase 5 is 90% by mass or more, or may be 95% by mass or more, or 100% by mass or less, or may be 99% by mass or less. The fourth phase 5 may further contain a minor component. The minor component may be at least one selected from ruthenium and iridium. The minor component content in the fourth phase 5 is 10% by mass or less. As shown in FIGS. 4F and 5F, the fourth phase 5 does not contain gold. The fourth phase 5 may contain only platinum and not contain any minor components.

[0042] As shown in FIG. 5D , when the first phase 2 further contains platinum as a minor component, the platinum content in the first phase 2 is lower than the platinum content in the fourth phase 5. In other words, the platinum content in the fourth phase 5 is higher than the platinum content in the first phase 2. The ratio of the platinum content in the fourth phase 5 to the platinum content in the first phase 2 is 3 or more, or may be 7 or more, or may be 20 or less, or may be 15 or less. The platinum content in the fourth phase 5 is calculated based on the intensity of platinum in a characteristic X-ray intensity distribution image.

[0043] The average size of the fourth phase 5 is the same as that of the first phase 2, specifically, 0.2 mm or more, preferably 0.5 mm or more, and 2.0 mm or less, preferably 1.5 mm or less. The average size of the fourth phase 5 is determined by the same method as above.

[0044] The volume proportions of the first phase 2, the second phase 3, the third phase 4, and the fourth phase 5 in the jewelry metal 1 may be the same or different from one another and are 20% by volume or more, or may be 25% by volume or more, and are 35% by volume or less, or 30% by volume or less. The volume proportions of the first phase 2, the second phase 3, and the third phase 4 are determined by observation using a digital microscope.

[0045] [Method of manufacturing jewelry bullion 1] First, a first wire, a second wire, a third wire, and a fourth wire are prepared. The fourth wire is made of a platinum alloy or platinum. The shape of the fourth wire is the same as that of the first wire described above. The platinum alloy has the same composition as the fourth phase 5.

[0046] Next, the first to fourth wires are cut in the same manner as in the first embodiment to prepare gold alloy particles and platinum-containing particles, respectively. The platinum-containing particles are made of platinum alloy or platinum. The size of the platinum-containing particles is the same as that of the gold alloy particles.

[0047] Next, gold alloy particles, platinum-containing particles, and gold particles are blended. The blending ratio of the platinum-containing particles to a total of 100 parts by mass of gold alloy particles is 25 parts by mass or more and 75 parts by mass or less. The blending ratio of the platinum-containing particles to the total of the gold alloy particles, platinum-containing particles, and gold particles is 25% by mass or more and 45% by mass or less. The blending ratio of the gold particles to the total of the gold particles, gold alloy particles, and platinum-containing particles is 1% by mass or more and 10% by mass or less. The gold alloy particles, platinum-containing particles, and gold particles are mixed in the above ratios to prepare a mixture.

[0048] The mixture is then subjected to SPS. SPS forms a first phase 2, a second phase 3, a third phase 4, and a fourth phase 5, which correspond to the first gold alloy particles, the second gold alloy particles, the third gold alloy particles, and the platinum-containing particles, respectively. Gold diffuses (migrates) into the first phase 2, the second phase 3, and the third phase 4, respectively. However, gold does not diffuse (migrate) into the fourth phase 5. A plurality of platinum alloy particles (two to five particles) aggregate to form the fourth phase 5. This produces a jewelry bullion 1. The jewelry bullion 1 is then shaped and processed to produce jewelry 10 (see FIG. 3 ). A four-color pattern (e.g., a four-color camouflage pattern) based on the first phase 2, the second phase 3, the third phase 4, and the fourth phase 5 is visually recognized by a user in the jewelry 10.

[0049] [Modification of the second embodiment] A modified example of the second embodiment will be described with reference to Figs. 6 and 7. Fig. 6 is a processed secondary electron image of the jewelry bullion of Example 3 and an intensity distribution image of characteristic X-rays derived from metal elements. Fig. 7 is a processed secondary electron image of the jewelry bullion of Example 3 and an intensity distribution image of characteristic X-rays derived from metal elements. Fig. 7A is a secondary electron image. Fig. 7B is an intensity distribution image of characteristic X-rays derived from silver (Ag). Fig. 7C is an intensity distribution image of characteristic X-rays derived from copper (Cu). Fig. 7D is an intensity distribution image of characteristic X-rays derived from platinum (Pt). Fig. 7E is an intensity distribution image of characteristic X-rays derived from palladium (Pd). Fig. 7F is an intensity distribution image of characteristic X-rays derived from gold (Au). In each of Figs. 6A to 6F, a process has been performed to draw boundaries between the phases of Figs. 7A to 7F.

[0050] As shown in Fig. 7D, in this modification, the first phase 2 does not further contain platinum as a minor component (see reference numeral 2 in Fig. 5D). In other words, the first phase 2 does not contain platinum, and the minor component is only palladium. [Example]

[0051] [Example 1] A jewelry bullion 1 of Example 1 was produced in accordance with the first embodiment.

[0052] A first wire, a second wire, and a third wire were prepared, each having the composition shown in Table 1. The diameter of each of the first wire, the second wire, and the third wire was 0.4 mm.

[0053] Next, the gold alloy particles and gold particles were mixed in the amounts shown in Table 1 to prepare a mixture.

[0054] Subsequently, the mixture was subjected to SPS to produce jewelry bullion 1. The SPS conditions were as follows. SPS equipment: LABOX 650F, manufactured by Sinterland Pressure: 50MPa Sintering temperature: 800℃ Holding time: 5 minutes An intensity distribution image of characteristic X-rays was taken on the surface of the jewelry bullion 1. The conditions are as follows: Electron probe microanalyzer: JXA-8230, manufactured by JEOL Ltd. Accelerating voltage: 20 kV Irradiation current: 5.0×10 -8 A

[0055] A secondary electron image of the jewelry bullion 1 of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements are shown in Figure 2. A processed image of the secondary electron image of the jewelry bullion 1 of Example 1 and an intensity distribution image of characteristic X-rays derived from metal elements is shown in Figure 1. When each phase (88 phases in total) in the jewelry bullion 1 was observed using a digital microscope (DMS1000, manufactured by Leica Microsystems), the average size of each of the first phase 2, second phase 3 and third phase 4 was 0.75 mm.

[0056] [Example 2] A jewelry bullion 1 of Example 2 was produced in accordance with the first embodiment.

[0057] Jewelry bullion 1 was produced in the same manner as in Example 1, and then SPS was carried out.

[0058] However, in Example 2, a fourth wire was used in addition to the first, second, and third wires. The diameter of the fourth wire was 0.4 mm. A mixture was prepared by mixing gold alloy particles, platinum-containing particles, and gold particles in the amounts listed in Table 1. A secondary electron image of the jewelry bullion 1 of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements are shown in Figure 5. A processed secondary electron image of the jewelry bullion 1 of Example 2 and an intensity distribution image of characteristic X-rays derived from metal elements are shown in Figure 4. When each phase (33 phases in total) in the jewelry bullion 1 was observed using the digital microscope described above, the average size of each of the first phase 2, second phase 3, third phase 4, and fourth phase 5 was 0.72 mm.

[0059] [Example 3] A jewelry bullion 1 of Example 3 was produced in accordance with the modified example of the second embodiment.

[0060] Jewelry bullion 1 was produced in the same manner as in Example 2, and then SPS was carried out.

[0061] However, the diameter of each of the first, second, third, and fourth wires was 0.5 mm. A secondary electron image of the jewelry bullion 1 of Example 3 and an intensity distribution image of the characteristic X-rays derived from the metal elements are shown in Figure 7. A processed image of the secondary electron image of the jewelry bullion 1 of Example 3 and an intensity distribution image of the characteristic X-rays derived from the metal elements is shown in Figure 6. When each phase (38 phases in total) in the jewelry bullion 1 was observed using the digital microscope described above, the average size of each of the first phase 2, second phase 3, third phase 4, and fourth phase 5 was 0.73 mm.

[0062] [Table 1]

[0063] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 1 jewelry bullion, 2 first phase, 3 second phase, 4 third phase, 5 fourth phase, 10 jewelry, 11 ring, 12 outer surface, 13 inner surface, 14 end surface.

Claims

1. The alloy comprises a first phase, a second phase, and a third phase that are not mixed with each other and contain gold as a main component; the first phase contains palladium as a minor component; The second phase contains copper and silver as minor components, The third phase contains copper and silver as minor components, the copper content in the second phase is higher than the copper content in the third phase; the silver content in the third phase is higher than the silver content in the second phase; A jewelry bullion, wherein the first phase, the second phase, and the third phase each have an average size of 0.2 mm or more and 2.0 mm or less.

2. The alloy comprises a first phase, a second phase, and a third phase that are not mixed with each other and contain gold as a main component; the first phase contains palladium as a minor component; The second phase contains copper and silver as minor components, The third phase contains copper and silver as minor components, the copper content in the second phase is higher than the copper content in the third phase; the silver content in the third phase is higher than the silver content in the second phase; a fourth phase immiscible with each of the first, second and third phases; the fourth phase does not contain gold and contains platinum as a main component, The average size of the fourth phase is 0.2 mm or more and 2.0 mm or less.

3. The alloy comprises a first phase, a second phase, and a third phase that are not mixed with each other and contain gold as a main component; the first phase contains palladium as a minor component; The second phase contains copper and silver as minor components, The third phase contains copper and silver as minor components, the copper content in the second phase is higher than the copper content in the third phase; the silver content in the third phase is higher than the silver content in the second phase; a fourth phase immiscible with each of the first, second and third phases; the fourth phase does not contain gold and contains platinum as a main component, the first phase further contains platinum as a minor component, The content of platinum in the fourth phase is higher than the content of platinum in the first phase. Jewelry bullion.

4. a fourth phase immiscible with each of the first, second and third phases; The fourth phase does not contain gold and contains platinum as a main component.

2. The jewelry bullion according to claim 1.

5. 3. The jewelry bullion according to claim 2, wherein the first phase, the second phase, and the third phase each have an average size of 0.2 mm or more and 2.0 mm or less.

6. the first phase further contains platinum as a minor component, 3. The jewelry bullion according to claim 2, wherein the content of platinum in the fourth phase is higher than the content of platinum in the first phase.

7. 4. The jewelry bullion according to claim 3, wherein the first phase, the second phase, and the third phase each have an average size of 0.2 mm or more and 2.0 mm or less.

8. 8. The jewelry bullion according to claim 7, wherein the average size of the fourth phase is 0.2 mm or more and 2.0 mm or less.

9. 9. An article of jewellery, the material being a jewellery bar according to any one of claims 1 to 8.

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