Idocrase Facet / Faceting Information
Idocrase / Vesuvianite
Color: Green to olive/green, yellow/green
Moh’s Hardness: 6.5
Refractive Index: 1.71
Critical Angle: 35.79°
Specific Gravity: 3.32-3.42
Fracture: Uneven, splintery
Heat Sensitivity: Low
Birefringence (double refraction): Weak (.005)
Crystal Structure: Tetragonal Cutting:
Treatments: Generally none
What I prefer to polishing with: Alumina oxide on a Tin lap
Jeff’s Comments: Idocrase is actually pretty rare… Most material is slightly sleepy/silky but it facets a very nice green stone for anybody’s gemstone collection. Vargas in faceting for Amateur says (p253). “This material handles easily with care. Most rough is flawed, and flawless gems are small and rare.”
Design Notes: About any Tourmaline, Topaz designs will work well. I prefer checker boards because they help hide the silk.
Design Links: Cornered – This is great for clear rough if you have a piece that will work.