Gemstone Crown Facet Angles for Star Appearance

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Solution Overview

Problem

Existing gemstone cutting technologies struggle to produce gemstones with a star-shaped appearance economically, as they require complex grinding to remove material between the rays, which is inefficient and not achievable in prior art gemstones with uniform light yield.

Innovation Solution

A gemstone design featuring a crown with specific facet angles (α = 22.5° ± 3° and β = 34° ± 3°) and a pavilion with angles (43.5° ± 3° and 50° ± 3°) to create a star-shaped appearance without material removal, enhancing light intensity and contrast for a star-like visual effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If complex grinding technology is used to remove material between the rays to create a star shape, then the gemstone achieves a star-shaped appearance, but the manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvestar-shaped appearanceVSAvoidgrinding technology complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

Instead of removing material to create the star shape (subtraction approach), the patent applies material selectively to the crown facets in a specific pattern (addition approach). The star-shaped appearance is achieved by depositing or applying substance only to certain facets that form the rays, rather than grinding away material between them. This inverts the traditional manufacturing logic from removal to addition.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The crown facets are divided into two distinct groups: a first group forming the rays of the star and a second group forming the spaces between the rays. This segmentation allows selective application of material or treatment to specific facets, creating the star pattern without requiring complex overall shaping operations. Each facet group can be treated independently to achieve the desired visual effect.

Inventive Principle:
Principle #1Segmentation

2Shape

If material is removed between the rays to create a star shape, then the gemstone has a star-shaped appearance, but the productivity and manufacturing efficiency decrease

Engineering Contradiction:
Improvestar-shaped appearanceVSAvoidmanufacturing efficiency
Core Design Contradiction:
ShapeVSProductivity

Solution Approach 1:

The patent inverts the manufacturing approach from subtractive (removing material between rays) to additive (applying material to facets forming rays). This allows the star pattern to be created through selective faceting and material application during the cutting process itself, rather than requiring subsequent complex removal operations, thereby improving manufacturing efficiency.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The star-shaped pattern is created during the initial cutting and faceting process rather than as a subsequent operation. By planning the facet arrangement and material application in advance during the cutting stage, the patent eliminates the need for later complex material removal operations, streamlining the manufacturing process and improving productivity.

Inventive Principle:
Principle #10Preliminary action

3Illumination intensity

If uniform light yield is achieved across the entire stone surface, then the gemstone has consistent appearance, but the star-shaped appearance cannot be achieved

Engineering Contradiction:
Improveuniform light yieldVSAvoidstar-shaped appearance
Core Design Contradiction:
Illumination intensityVSShape

Solution Approach 1:

The patent applies different properties to different regions of the gemstone surface. The crown facets are divided into two groups with potentially different material applications or treatments. The first group of facets (forming rays) receives different treatment than the second group (forming spaces between rays), creating local variations in light reflection and refraction that produce the star-shaped appearance while maintaining overall aesthetic quality.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The gemstone achieves a star-shaped appearance with significant contrast in light yield, creating a visually striking effect without the need for material removal, while maintaining a pentagonal outline and high light return, making it more economical to produce.

Implementation Method 1

The light output is based on countless internal light reflections. These light reflections are caused by the individual facets, which are in special angular relationships to one another that characterize the respective cut.

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The light output is based on countless internal light reflections. These light reflections are caused by the individual facets, which are in special angular relationships to one another that characterize the respective cut.

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3068254B1Gem having a stellar appearance
Publication Date: 2018.05.23 D SWAROVSKI & CO
  • EP3068254B1 patent drawingFigure 1a~1c
  • EP3068254B1 patent drawingFigure 1d~1f
  • EP3068254B1 patent drawingFigure 1g~2b

AI summary

Disclosed is a gem (1) that has a stellar appearance. Said gem (1) comprises a crown (2) having a plurality of crown facets, including a first group (6) of crown facets that taper in the direction of a girdle (4) and extend at an angle (α) of 22.5° ± 3°, preferably 22.5° + 2° from the girdle plane (E), and a second group (7) of crown facets that adjoin the girdle (4) by their large side and extend at an angle (ß) of 34° ± 3°, preferably 34° ± 2° from the girdle plane (E). Also disclosed is an arrangement comprising a gem.