APOPHYLLITE: India (1.3, 8.6, 2.4)
Apophyllite is very brittle and fragile, with an extremely perfect and easy cleavage. It is unsuited for jewelry, but colorless Apophyllite is perhaps the whitest of all gems. The cut stones are so devoid of any trace of color that they almost appear silvery. The perfect cleavage dictates an orientation with the table of a faceted stone not perpendicular to the long axis of the crystals. The green, iron-rich Apophyllite from India occurs in magnificent crystal groups, but facetable material is quite scarce and usually smaller than the colorless variety.
Apophyllite Value
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Apophyllite Information
| Data | Value |
| Name | Apophyllite |
| Crystallography | Tetragonal. Crystals pseudo cubic; tabular, prismatic, sometimes pyramidal. |
| Colors | Colorless, white, grayish, pale yellow, pale green, dark green, reddish. |
| Luster | Vitreous, pearly on cleavage. |
| Hardness | 4.5 – 5 |
| Density | 2.3-2.5 |
| Birefringence | 0.001 or less. May appear isotropic. |
| Cleavage | Perfect 1 direction. Fracture uneven. Brittle. |
| Stone Sizes | Apophyllites are seldom faceted, and rough to cut greater than 10 carats is very rare. Stones are usually colorless, though green Indian material is also cut. SI: 15.4 (colorless, step-cut) DG: 7.05 (colorless, Poona, India) PC: 24.92 (free-form, Poona, India) |
| Luminescence | None |
| Spectral | Not diagnostic |
| Formula | KCa4Si8O20(F, OH)· 8H2O |
| Pleochroism | None |
Optics: o= 1.53-1.54; e= 1.53-1.54 (variable). Optically (+) or (-); uniaxial
Occurrence: Secondary mineral in basic igneous rocks, such as basalts and traprocks.
New Jersey; Oregon; Washington; Colorado; Michigan; Virginia; Pennsylvania.
Guanajuato, Mexico; Brazil; Canada; Sweden; Scotland;
Germany, Ireland; Faroe Islands, Iceland; Bay of Fundy, Nova Scotia
Bombay, India: colorless crystals and also intense apple green color, due to Fe (Poona, India: o = 1.530, e= 1.533, birefringence 0.003, S.G. = 2.37).
Comments: Apophyllite is very brittle and fragile, with an extremely perfect and easy cleavage. It is unsuited for jewelry, but colorless Apophyllite is perhaps the whitest of all gems. The cut stones are so devoid of any trace of color that they almost appear silvery. The perfect cleavage dictates an orientation with the table of a faceted stone not perpendicular to the long axis of the crystals. The green, iron-rich Apophyllite from India occurs in magnificent crystal groups, but facetable material is quite scarce and usually smaller than the colorless variety.
Name: From Greek words describing the tendency of Apophyllite to exfoliate when strongly heated.
