Helidore Facet / Faceting Information


Maiden's Cross Helidore Helidore (Beryl) Color: yellow, yellow/green Moh’s Hardness: 7.5-8 Refractive Index: 1.57-1.60 Critical Angle: 39.97° Specific Gravity: 2.65-2.75 Cleavage: None Fracture: Conchoidal, tough Dispersion: .014 Heat Sensitivity: Slightly Dichroism: weak (gold-yellow to greenish-yellow) Birefringence (double refraction): Weak (.006-.009) Crystal Structure: Hexagonal Treatments: Often heat treated and irradiated… What I prefer to polishing with: Cerium oxide with a Spectra Ultralap. Jeff’s Comments: Cuts and polishes like any other Beryl, usually no problems… I like to use a 1200 Nu Bond lap for pre-polish, it makes the polishing stage faster and easier. Orientating on the “c” is slightly better. Watch for silk and lilly pad type of inclusions perpendicular to the “c” axis. Design Notes: About any design will work well… I prefer a deeper design and often cut Barions… Design Links: Aqua Cisor – This is great for clear rough if you have a piece that will work… Blue Ice – Designed for very long crystals

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.