Editorial Feature

Damiaoite – Occurrence, Properties, and Distribution

Aug 29 2013

Damiaoite was named after its type locality, namely, the village of Damiao, China.

Properties of Damiaoite

The following are the key properties of Damiaoite:

Cell Data
- Space group: Fm3m.
- a = 6.363(4)
- Z = 4.
Crystal Data
- Cubic
- Point group: 4/m 32/m.
- Polycrystalline globules, to 2 mm
- Exsolved from yixunite
- X-ray powder pattern: 2.25 (100), 1.299 (80), 1.006 (70), 1.92 (60), 1.59 (60), 1.125 (60), 3.67 (50).
Chemical Composition

Elements Content 1 Content 2

In 53.5 54.07

Pt 45.6 45.93

Total 99.1 100
Optical Properties
- Bright white with a yellowish tint when reflected in light.
- Optical class: Isotropic.
- R: (400) 65.4, (420) 51.4, (440) 49.3, (460) 49.0, (480) 49.9, (500) 52.0, (520) 55.0, (540) 58.5, (560) 62.5, (580) 66.5, (600) 70.2, (620) 74.5, (640) 77.7, (660) 81.5, (680) 84.2, (700) 86.9.

Elements	Content 1	Content 2
In	53.5	54.07
Pt	45.6	45.93
Total	99.1	100

Estimated Properties

Electron density	Bulk density (electron density) = 9.07 gm/cm³ note: Specific gravity of damiaoite = 10.9 gm/cm³
Photoelectric	PE_Damiaoite = 887.08 barns/electron U = PE_Damiaoite x ρElectron density = 8,043.05 barns/cm³
Fermion index	Fermion index = 0.15 Boson index = 0.85
Radioactivity	Damiaoite is not radioactive.

How to Identify Damiaoite

Damiaoite is identified in the field by its bright white color in an opaque form. It has a metallic lustre coupled with a black streak. This mineral has no cleavages and is spherical in structure. The density of damiaoite is 10.95 gm/cm³ with a hardness of 5 (approximate to apatite).

Global Distribution

Damiaoite is found only in China near the Damiao village and the Yixun River, which is 270 km north of Beijing in the Hebei Province.

Occurrence of Damiaoite and Useful Mineral Association

Damiaoite occurs in a metasomatic cobalt-copper-platinum-bearing vein, in garnet-amphibole pyroxenite, in contact with granite and anorthosite. It is often associated with minerals such as moncheite, cooperite, yixunite, cobaltian malanite, bornite, carrolite, sperrylite, magnetite, and chalcopyrite.