Editorial Feature

Carlsbergite – Occurrence, Properties, and Distribution

May 12 2014

Carlsbergite was named after the Carlsberg Foundation in Copenhagen, Denmark, which supported the recovery and cutting of the Agpalilik meteorite.

Properties of Carlsbergite

The following are the key properties of carlsbergite:

Cell Data
- Space group: Fm3m
- a = 4.16(3)
- Z = 4

Crystal Data
- Cubic
- Point group: 4/m 3 2/m
- As oriented platelets, to 30µm, and feathery to irregular grain-boundary precipitates
- X-ray powder pattern: 2.068 (100), 2.394 (80), 1.463 (80), 1.249 (60), 0.9260 (60), 0.8460 (60), 0.9496 (50)

Chemical Composition

Elements	Content 1	Content 2	Content 3
Cr	76.0 – 78.0	76.3	78.78
N	20.0 – 25.0	[21.4]	21.22
Ni	-	0.3	-
Fe	0.1 – 1.8	1.9	-
Mn	-	0.04	-
Co	-	0.03	-
Total	-	[100.0]	100.0

Optical Properties
- R: (481) 49.5, (546) 41.5, (590) 41.0, (644) 40.5

Estimated Properties

Electron density	Bulk density (electron density) = 5.72 g/cm³ note: Specific gravity of carlsbergite = 6.09 g/cm³
Photoelectric	PE_Carlsbergite = 18.07 barns/electron U=PE_Carlsbergite x ρ electron density= 103.39 barns/cm³
Fermion index	Fermion index = 0.28 Boson index = 0.72
Radioactivity	Carlsbergite is not radioactive

How to Identify Carlsbergite

Carlsbergite can be identified in the field by its gray color. Its opaque form has a metallic luster. The density of carlsbergite is 5.9 g/cm³ with a hardness of 7 – approximate to quartz.

Global Distribution

Carlsbergite was first noted in the Agpalilik (Cape York) iron meteorite. Since then it has been identified in more than 70 meteorites, mostly of Ga–Ge group IIIA, and also in groups I and IIA. In USA, for example, it was found in the following regions:

Arizona, Coconino Co. Winslow, Meteor Crater and vicinity
Canyon Diablo meteorite
Georgia, Oglethorpe Co. Smithonia meteorite
Kentucky, Kenton Co. Kenton County meteorite
Montana, Broadwater Co. Lombard meteorite
North Carolina, Cherokee Co. Murphy meteorite; Davidson Co. Lick Creek meteorite
Pennsylvania, Somerset Co. New Baltimore, New Baltimore meteorite

Occurrence of Carlsbergite and Useful Mineral Association

Carlsbergite occurs as minute platelets and grain boundary precipitates in kamacite and troilite, and as similar grains ringing daubreelite in iron meteorites. It is often associated with minerals such as kamacite, taenite, sphalerite, daubreelite, and troilite.