Editorial Feature

Aheylite – Occurrence, Properties, and Distribution

Jun 12 2014

Aheylite was named after Allen V. Heyl, an economic geologist associated with the U.S. Geological Survey. It is a part of the turquoise group.

Properties of Aheylite

The following are the key properties of aheylite:

Cell Data
- Space group: P1 or P1
- a = 4.229
- b = 6.931
- c = 7.862
- β = 99.61°
- Z = 4

Crystal Data
- Triclinic
- Point group: 1 or 1
- Interlocked in felted and matted aggregates to form botryoidal, spherulitic masses
- Radiating, prismatic groups, to 5mm
- X-ray powder pattern: 3.670 (100), 2.888 (67), 6.146 (43), 3.27 (37), 3.436 (36), 2.914 (34), 3.398 (25)

Chemical Composition

Elements	Content 1	Content 2
Al₂O₃	38.1	37.96
P₂O₅	35.4	35.23
H₂O⁺	18.5	17.89
FeO	4.14	8.92
ZnO	4.02	-
H₂O^-	0.08	0.00
Total	100.24	100.00

Optical Properties
- Optical class: Biaxial (+)
- n = ∼ 1.63

Estimated Properties

Electron density	Bulk density (electron density) = 2.86 g/cm³ note: Specific gravity of Aheylite = 2.85g/cm³
Photoelectric	PE_Aheylite = 3.92 barns/electron U = PE_Aheylite x ρ electron density = 11.20 barns/cm³
Fermion index	Fermion index = 0.0023 Boson index = 0.9976
Radioactivity	Aheylite is not radioactive

How to Identify Aheylite

Aheylite can be identified in the field by its blue-green color. Its transparent form has good cleavage. This mineral has a vitreous–dull luster, with a greenish-white streak. The fracture on this mineral is hackly-jagged, torn surfaces.

The density of aheylite is 2.85 g/cm³, with a hardness of 5 to 6 - between apatite and orthoclase.

Global Distribution

Aheylite is distributed in the following places:

Bolivia - In the Huanuni mine, Oruro
Australia - From the Bali Lo copper prospect, 11km west-south-west of Ashburton Downs homestead, Capricorn Range, Western Australia