Method for identifying production place of sea sapphire

Abstract

According to the method for identifying the producing area of the sea sapphire provided by the invention, through the technical scheme, the formation of the sea sapphire is closely related to a specific geological environment and a specific formation mechanism. Different conditions such as geological structures, magma activities and hydrothermal actions of different producing areas cause slight differences in chemical components of sea sapphire, such as contents and proportions of elements such as iron, aluminum and silicon. According to the main trace component information of the gemstone, through a big data analysis algorithm, the component characteristics of the main sea sapphire producing area in the world are identified, a new technical method is provided for identifying the producing area of the sea sapphire, and a basis is also provided for evaluating the value of the sea sapphire.

Description

Technical Field

[0001] The present invention relates to the technical field of gemstone mineral identification, and in particular to a method for identifying the origin of aquamarine. Background Art

[0002] Beryl is one of the most common beryllium-containing minerals and is formed only in specific geological environments. There are many types of beryllium deposits, of which three are dominant: granite pegmatite deposits, volcanic rock deposits, and carbonate rock deposits. These deposits are distributed all over the world, and the output of gem-grade crystalline beryl is usually related to granite pegmatites. Aquamarine is a blue subspecies of beryl, usually with a sea-like blue color and high transparency. As aquamarine deposits are discovered one after another around the world, establishing a method to distinguish aquamarines from different origins is of great significance to the jewelry trade. The currently disclosed technical method distinguishes the two subclasses of aquamarine, "Santa Maria" and "Super Santa Maria", based on the gemstone chromaticity coordinate information and the coloring element content information. This method improves the accuracy and efficiency of aquamarine subclass identification, but it is mainly used for aquamarines with higher color grades, lacks universal application for aquamarines of different qualities, and cannot be directly used for gemstone origin analysis. Summary of the invention

[0003] In order to make up for the shortcomings of the prior art, the present invention provides a method for identifying the origin of aquamarine. The formation of aquamarine is closely related to a specific geological environment and genetic mechanism. The different geological structures, magmatic activities, hydrothermal effects and other conditions in different origins may lead to slight differences in the chemical composition of aquamarine, such as the content and proportion of elements such as iron, aluminum, and silicon. This method identifies the composition characteristics of the world's major aquamarine producing areas based on the main and trace component information of the gemstones through a big data analysis algorithm, which not only provides a new technical method for the identification of the origin of aquamarine, but also provides a basis for the value assessment of aquamarine.

[0004] The present invention is achieved through the following technical solution: a method for identifying the origin of aquamarine, specifically comprising the following steps: S1 electron probe major element analysis: S1-1 Sample preparation: Use a carbon spraying instrument to coat the surface of the aquamarine sample to be tested with a 20nm carbon film to determine the area to be analyzed; S1-2 Select monitoring standards for each element: Plagioclase (Al), diopside (Si, Ca), rutile (Ti), rhodonite (Mn), chromite (Fe), albite (Na), olivine (Mg), sanuclear (K), apatite (P), pentlandite (Ni) and willemite (Zn) were selected as monitoring standards for the corresponding elements; S1-3 Determine the X-ray characteristic peaks of different elements in the sample: An electron probe was used to emit an electron beam with a spot size of 5 μm under the conditions of an acceleration voltage of 15 kV and a current of 20 nA to irradiate the surface of the aquamarine sample, thereby exciting characteristic X-rays of the elements contained in the sample, and the part with the highest X-ray intensity was selected as the peak position of the element to be measured; S1-4 Analyze the content of various elements in the sample to be tested The content of each element is quantitatively analyzed by ZAF, that is, the X-ray intensity of the sample and the known component monitoring standard is measured at the same time, and the percentage content of the corresponding element in the sample is obtained through correction calculation. 样品 : C 样品 =G*(I 样品 / I 标样 ) * C 标样 Where G is the correction factor. When using the matrix correction method (ZAF), G=G Z * G A * G F In the formula, G Z is the atomic number correction factor, G A is the absorption correction factor, G F is the fluorescence correction factor. Through the electron probe test, the content of main elements including Si, Al, Fe, Na, and K in aquamarine is detected, the content of characteristic elements in aquamarine is identified, and the basic characteristics of aquamarine are constrained; S2 Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS) Trace Element Analysis: S2-1 Sample preparation: Clean the sample and use the well-polished crystal plane of the sample to be tested as the test plane.

[0005] S2-2 Laser point selection: Select and mark the aquamarine to be tested in the laser software, and adjust the laser ablation parameters to 30 μm for each analysis point, 6 Hz repetition frequency, and 90 s ablation time; S2-3 mass spectrometer data collection: After operating the laser software to start ablation, the mass spectrometer ionizes the ablation sample under high vacuum conditions, separates and collects different ions according to the mass-to-charge ratio of the ions, and amplifies their output signals; S2-4 obtains the content of various elements in the sample: The data analysis system converts the number of ions detected by the mass spectrometer into a spectrum, and uses standard samples of known composition to calibrate the content of each element in the sample to obtain the content of trace elements including Li, Rb, Cs, and Mn in aquamarine.

[0006] As a preferred option, the main and trace element composition information of aquamarine shows that Fe is the most important substituent of octahedral coordinated Al. Aquamarines from different origins are divided into high Al and high Fe types according to the Al-Fe content.

[0007] As a preferred solution, the main and trace element composition information of aquamarine is divided into a high alkali metal group and a low alkali metal group according to the Li-Cs content.

[0008] The present invention has the following beneficial effects compared with the prior art due to the adoption of the above technical solutions: the testing method used in the present method is an in-situ, micro-area, near-nondestructive method. It can effectively, comprehensively and accurately obtain the composition information of aquamarine, so as to make a reliable judgment on its origin. The electron probe and laser ablation inductively coupled plasma mass spectrometer belong to micro-area testing, and the ablation pits are invisible to the naked eye, which does not affect the appearance and original value of the gemstone. Compared with other methods, this method has no restrictions on sample color and transparency ( Figure 3 ), and improved the accuracy of origin identification results through big data analysis methods.

[0009] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 Comparison of major element compositions of aquamarine from different origins (a) Al to Fe (b) Al to octahedral substitution ions; Figure 2 This is a comparison chart of the trace element Li and Cs content in aquamarine from different origins; Figure 3 The existing analysis methods are mainly classified based on the color and trace element content information of aquamarine. DETAILED DESCRIPTION

[0011] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0012] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0013] Combine the following Figure 1 to Figure 2 The method for identifying the origin of aquamarine according to an embodiment of the present invention is specifically described.

[0014] like Figure 1 , Figure 2 As shown, the present invention proposes a method for identifying the origin of aquamarine, which specifically includes the following steps: S1 electron probe major element analysis: S1-1 Sample preparation: Use a carbon spraying instrument to coat the surface of the aquamarine sample to be tested with a 20nm carbon film to determine the area to be analyzed; S1-2 Select monitoring standards for each element: Plagioclase (Al), diopside (Si, Ca), rutile (Ti), rhodonite (Mn), chromite (Fe), albite (Na), olivine (Mg), sanuclear (K), apatite (P), pentlandite (Ni) and willemite (Zn) were selected as monitoring standards for the corresponding elements; S1-3 Determine the X-ray characteristic peaks of different elements in the sample: An electron probe was used to emit an electron beam with a spot size of 5 μm under the conditions of an acceleration voltage of 15 kV and a current of 20 nA to irradiate the surface of the aquamarine sample, thereby exciting characteristic X-rays of the elements contained in the sample, and the part with the highest X-ray intensity was selected as the peak position of the element to be measured; S1-4 Analyze the content of various elements in the sample to be tested The content of each element is quantitatively analyzed by ZAF, that is, the X-ray intensity of the sample and the known component monitoring standard is measured at the same time, and the percentage content of the corresponding element in the sample is obtained through correction calculation C sample: C sample = G*(I sample / I standard sample) * C standard sample Where G is the correction factor. When using the matrix correction method (ZAF), G=G Z * G A * G F In the formula, G Z is the atomic number correction factor, G A is the absorption correction factor, G F is the fluorescence correction factor. Through the electron probe test, the content of main elements including Si, Al, Fe, Na, and K in aquamarine is detected, the content of characteristic elements in aquamarine is identified, and the basic characteristics of aquamarine are constrained; S2 Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS) Trace Element Analysis: S2-1 Sample preparation: Clean the sample and use the well-polished crystal plane of the sample to be tested as the test plane.

[0015] S2-2 Laser point selection: Select and mark the aquamarine to be tested in the laser software, and adjust the laser ablation parameters to 30 μm for each analysis point, 6 Hz repetition frequency, and 90 s ablation time; S2-3 mass spectrometer data collection: After operating the laser software to start ablation, the mass spectrometer ionizes the ablation sample under high vacuum conditions, separates and collects different ions according to the mass-to-charge ratio of the ions, and amplifies their output signals; S2-4 obtains the content of various elements in the sample: The data analysis system converts the number of ions detected by the mass spectrometer into a spectrum, and uses standard samples of known composition to calibrate the content of each element in the sample to obtain the content of trace elements including Li, Rb, Cs, and Mn in aquamarine. The elements in aquamarine with potential significance for origin identification are analyzed to further provide a basis for origin identification.

[0016] By obtaining the main and trace element composition information of aquamarine, Fe is the most important substituent of octahedral coordinated Al. Aquamarine from different origins is divided into high Al and high Fe according to the Al-Fe content. For example, Yukon aquamarine in Canada belongs to the high Fe group, and Altay aquamarine in Xinjiang Uygur Autonomous Region belongs to the high Al group. Aquamarine is divided into high alkali metal group and low alkali metal group according to the Li-Cs content. For example, Mogok aquamarine in Myanmar belongs to the high alkali metal group, and Minas Gerais aquamarine in Brazil and Altay aquamarine in Xinjiang Uygur Autonomous Region belongs to the low alkali metal group. Further, the data algorithm is used to compare and match the aquamarine composition information of known origins in the database to achieve origin identification.

[0017] In the description of the present invention, the term "plurality" refers to two or more than two. Unless otherwise clearly defined, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention; the terms "connection", "installation", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0019] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for identifying the origin of aquamarine, characterized in that: The specific steps include: S1 electron probe major element analysis: S1-1 Sample preparation: Use a carbon spraying instrument to coat the surface of the aquamarine sample to be tested with a 20nm carbon film to determine the area to be analyzed; S1-2 Select monitoring standards for each element: Plagioclase (Al), diopside (Si, Ca), rutile (Ti), rhodonite (Mn), chromite (Fe), albite (Na), olivine (Mg), sanuclear (K), apatite (P), pentlandite (Ni) and willemite (Zn) were selected as monitoring standards for the corresponding elements; S1-3 Determine the X-ray characteristic peaks of different elements in the sample: An electron probe was used to emit an electron beam with a spot size of 5 μm under the conditions of an acceleration voltage of 15 kV and a current of 20 nA to irradiate the surface of the aquamarine sample, thereby exciting characteristic X-rays of the elements contained in the sample, and the part with the highest X-ray intensity was selected as the peak position of the element to be measured; S1-4 Analyze the content of various elements in the sample to be tested The content of each element is quantitatively analyzed by ZAF, that is, the X-ray intensity of the sample and the known component monitoring standard is measured at the same time, and the percentage content of the corresponding element in the sample is obtained through correction calculation. 样品 : C 样品 =G*(I 样品 / I 标样 ) * C 标样 Where G is the correction factor. When using the matrix correction method (ZAF), G=G Z * G A * G F In the formula, G Z is the atomic number correction factor, G A is the absorption correction factor, G F is the fluorescence correction factor; the content of main elements including Si, Al, Fe, Na, and K in aquamarine is detected by electron probe testing, the content of characteristic elements in aquamarine is identified, and the basic characteristics of aquamarine are constrained; S2 Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS) Trace Element Analysis: S2-1 Sample preparation: Clean the sample and use the well-polished crystal plane of the sample to be tested as the test plane; S2-2 Laser point selection: Select and mark the aquamarine to be tested in the laser software, and adjust the laser ablation parameters to 30 μm for each analysis point, 6 Hz repetition frequency, and 90 s ablation time; S2-3 mass spectrometer data collection: After operating the laser software to start ablation, the mass spectrometer ionizes the ablation sample under high vacuum conditions, separates and collects different ions according to the mass-to-charge ratio of the ions, and amplifies their output signals; S2-4 obtains the content of various elements in the sample: The data analysis system converts the number of ions detected by the mass spectrometer into a spectrum, and uses standard samples of known composition to calibrate the content of each element in the sample to obtain the content of trace elements including Li, Rb, Cs, and Mn in aquamarine.

2. A method for identifying the origin of aquamarine according to claim 1, characterized in that ,The main and trace element composition information of the aquamarine, Fe is the most important substituent of octahedral coordinated Al, and aquamarines from different origins are divided into high Al type and high Fe type according to the Al-Fe content.

3. The method for identifying the origin of aquamarine according to claim 1, characterized in that , the main and trace element composition information of the aquamarine is divided into a high alkali metal group and a low alkali metal group according to the Li-Cs content.

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