One of six end members of the garnet family. Pure almandine garnets are virtually non-existent. There is always a mixture with pyrope and/or spessartite. To be classed as an almandine SG should be >3.93 and RI >1.77 (There is a small difference in limit values depending on source).

Physical properties:

Chemistry: Fe+23Al2(SiO4)3
Hardness: 7–7,5
SG: 3,93–4,32
Cleavage: None
Toughness: Sometimes slightly brittle
Heat sensitivity: None

Optical properties

RI: 1,77–1,83
Dispersion: 0,024 (medium)
Birefringence None
Pleochroism: None
Critical angle: 34,5°

Facet angles (pavilion/crown):

Vargas: 41°/39°
Olson: 39°/37°
Soukup: 42°/37°
Roth: 42°/37°
MDR: 42°/37°
Schlagel: 40°/36°
Hashnu: 41°/39°
Sinkankas: 40°/40°
GIA: 42°/37°
Perkins: 42°/37°
Raytech: 40°/38°

Cutting lap:

Medium – fine

Facet polishing:

Vargas: Alumina oxide on tin/lead, tin oxide on tin
Olson: Chrome oxide on tin
Soukup: Alumina oxide on tin or tin/lead
Christiansen: Alumina oxide on tin/lead, tin oxide on tin
Perkins: Alumina oxide on BATT or Corian
MDR: Tin- or alumina oxide on tin, alumina oxide on type metal

Cabochon polishing:

Olson: Chrome oxide on leather
Christiansen: Alumina, tin or chrome oxide on leather or wood
Cox: Alumina or chrome oxide on leather, Cerium oxide on felt
Covington: Chrome or cerium oxide on felt


For best yield


None known

Hint !

Almandine can sometimes be too brittle for new cutting laps.

There are no products to list in this category.

This web site uses cookies only to keep track of your chosen language and currency, and a id number for your shopping basket. It stores no information for marketing or statistics.
I accept these cookies