Ametrine Facet / Faceting Information


Ice cut in Ametrine

Ametrine (Quartz)

Color: Amethyst/Citrine mix – purple, violet to red-violet, blue/purple with yellow/gold orange
Moh’s Hardness: 7
Refractive Index: 1.544-1.553
Critical Angle: 40.49°
Specific Gravity: 2.63-2.65
Cleavage: None
Fracture: Conchoidal
Dispersion: .013
Heat Sensitivity: Can be… but is usually not a problem
Dichroism: very weak
Birefringence (double refraction): Weak (.009)
Crystal structure: Hexagonal

Treatments: Generally none.

What I prefer to polishing with: Cerium oxide with a Spectra Ultralap.

Jeff’s Comments: Cuts and polishes like any other Quartz, usually no problems… I like to use a 1200 Nu Bond lap for pre-polish, it makes the polishing stage faster and easier. Watch for stress flaws around the color zone changes. Some very interesting effects can be created by orientating the color zones differently.

Design Notes: About any Quartz design will work well. As the rough gets more saturated, I prefer cheacker boards and bar cuts.

Design Links: 4-Way Stop – This is great for saturated rough if you have a piece that will work in the shape…
Be Still My Heart – Good in about any Quartz
CheckMate – Neat in medium color Quartz
Light House – Nice in any Quartz
Utopia – Classic Barion pear

Gram Faceting Archive of Information
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.