Skutterudite

It's advisable to handle skutterudite carefully to avoid generating dust and wash hands thoroughly afterward. When cutting or polishing skutterudite, wear a dust mask to prevent inhaling heavy metal particles. Store skutterudite in a sealed container in a well-ventilated area, away from children and pets. For those involved in crystal healing, never put it in your mouth.

The crystal structure of the skutterudite mineral was determined in 1928 by Oftedahl to be cubic, belonging to space group Im-3 (number 204). The unit cell can be considered to consist of eight smaller cubes made up of the Co atoms. Six of these cubes are filled with (almost) square planar rings of As, each of which is oriented parallel to one of the unit cell edges. The As atoms then form octahedra with Co in the center. In crystallographic terms, the Co atoms occupy the 8c sites, while the As atoms occupy the 24g sites. The position of the Co atoms within the unit cell is fixed, while the positions of the As atoms are determined by the parameters x and y. It has been shown that for the As-rings to be fully square, these parameters must satisfy the Oftedahl relation x + y = 1/2. Any deviation from this relation yields a rectangular configuration of the As atoms; indeed, this is the case for all known compounds with this structure, and the As atoms do not form a perfect octahedra. Together with the unit cell size and the assigned space group, the aforementioned parameters fully describe the crystal structure of the material. This structure is often referred to as the skutterudite structure.

Skutterudite is commonly mined as a source of cobalt and nickel, which then may be used for a variety of other purposes. Cobalt has many applications, including its use in batteries, dyes and pigments (due to its rich blue color), and alloys. Nickel is also used in batteries, but also is used to make coins and metal sheeting.

Skutterudite was discovered in Skuterud Mines, Modum, Buskerud, Norway, in 1845. Smaltite is an alternative name for the mineral. Notable occurrences include Cobalt, Ontario, Skuterud, Norway, and Franklin, New Jersey, in the United States. The rare arsenide minerals are classified in Dana's sulfide mineral group, even though it contains no sulfur.