Helidore Facet / Faceting Information

A guide to Helidore Faceting. Essential information on Helidore faceting that includes tips and guides on cuts and polishes together with helpful details.

Home Learning Center Jewelry and Lapidary Cutting Information for Specific GemstonesHelidore Facet / Faceting Information

By Jeff R. Graham

Helidore Facet / Faceting Information

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

Jeff R. Graham

The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.

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Helidore Facet / Faceting Information