Chrysoberyl
Alexandrite
Alexandrite is the colour-change variety of chrysoberyl: teal to green in daylight, red to purple under warm incandescent light.
Alexandrite
At a glance
- Mineral
- Chrysoberyl, coloured by chromium
- Refractive index
- 1.746
- Dispersion (C–F)
- 0.009
- Specific gravity
- 3.73
- Mohs hardness
- 8.5
- Wear
- Hard and tough: excellent for rings.
Alexandrite in Jart
The look in the studio's material library, with the values the renderer uses.
| Stone | Colour | RI | Dispersion C–F | Abbe | SG | Colour depth |
|---|---|---|---|---|---|---|
| Alexandrite | #3f9c86 | 1.746 | 0.009 | 83 | 3.73 | 9 mm |
RI refractive index (nd). Dispersion C–F nF − nC, the spread between blue and red light; many gem tables quote the B–G figure instead (diamond 0.044, here 0.025). Abbe number: lower means more fire. SG specific gravity, used for carat estimates in Design Facts. Colour depth the path through the stone after which white light takes the stone's full colour; shorter paths look paler.
How it renders
With a refractive index of 1.746, a polished alexandrite facet reflects 7.4% of light that meets it face-on (diamond: 17.2%). Light inside the stone that meets a facet more than 34.9° from straight on cannot leave and is reflected back in; the smaller that angle, the more light a good cut returns to the eye (diamond 24.4°, quartz 40.4°).
Its dispersion (C–F) is 0.009, 36% of diamond's, which sets how much fire, the flashes of colour, a render shows under small, bright lights.
Jart renders alexandrite in its daylight colour. Colour change under different light is not simulated yet (tracker #210), so a render under warm lighting will not turn red.
- 1 mm
- 3 mm
- 6 mm
- 10 mm
Related stones
All gemstones · Metals · Stone and metal pairings · Finishes
Render alexandrite on your own design.
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