Apatite Faceting Information
Apatite is a name for the group of Calcium Phosphate minerals that come in various colors. Several information on Apatite Faceting, cuts and polishes.
1 Minute Read
Apatite
Color: blue, green, yellow, pink, violet, colorless.
Moh's Hardness: 5
Refractive Index: 1.632-1.646
Critical Angle: 37.84°
Specific Gravity: 3.17-3.23
Cleavage: Poor, imperfect
Fracture: Conchoidal, brittle
Dispersion: .013-.016
Heat Sensitivity: High
Dichroic: Strong to weak depending on the color
Birefringence (double refraction): Weak (.002-.004)
Crystal Structure: Hexagonal
Treatments: Blue/green, blue Apatite is usually heat treated to bring out the blue color and to remove silk.
What I prefer to polishing with: Alumina oxide and a tin lap, Spectra Untralaps work well too,vinegar can ease polishing difficulties. I use it straight (no water), just a few drops of vinegar and polish…
Jeff's Comments: This material is difficult to get clean and any decent size. The crystals are typically included and the cleavage can be quite a problem. Cold dop only, heat can cause the cleavage to run…
Use a fine lap, like a worn 600 to rough in… It cuts fairly easily and is quite different, polishing is where you will run into problems. It can be brittle, sharp corners may chip because of brittleness and just hard to get a scratch free polish.
I like the color of this material but it is basically a novelty stone, it is too soft to set in jewelry as a general rule.
Design Notes: About any Quartz, Topaz, or Tourmaline design.
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.
Related Articles
Sphalerite Facet / Faceting Information
Hyacinth Zircon Faceting Information
Bixbite Facet / Faceting Information
Hiddenite Faceting Information
Latest Articles
Classic Engagement Ring Stones
Broken Bangle — The Blunder-Besmirched History of Jade Nomenclature: Book Review
Cuprite Value, Price, and Jewelry Information
Gemstone Radiation Treatment
Never Stop Learning
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Get Gemology Insights
Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!