Paramelaconite

Paramelaconit is a very rarely occurring mineral from the mineral class of oxides and hydroxides. It crystallizes in the tetragonal crystal system having a chemical composition CU21 Cu22 O3 and is up to 7.5 cm large prismatic crystals of black color.

Etymology and history

Paramelaconit was first found in the U.S. state of Arizona in 1890 by AE Foote in the type locality, the Copper Queen mine in Bisbee. The mineral was investigated in 1891 by August King, who described it as tetragonal modification of copper ( II ) oxide and dimorphic to Tenorite. From this derives the name of the mineral, as Melaconit is a now obsolete alternative name for Tenorite. The exact composition of 1941 Clifford Frondel Paramelaconits could enlighten by X-ray structural analysis.

Classification

In the classification by Strunz Tenorite is counted among the oxides with a ratio of metal to oxygen of 2:1 and 1:1. After the 8th edition forms a group together with Crednerit, delafossite, Mcconnellit and Tenorite. The 9th edition, it forms, with its own sub-group of the oxides, with a ratio of metal to oxygen of 2:1 ( and 1.8:1 ).

In the classification by Dana, it forms a separate subgroup of the simple, unclassified oxides.

Education and Locations

Paramelaconit very rare forms as a secondary mineral under hydrothermal conditions in copper deposits. It is associated with cuprite, Tenorite, Connellite, malachite, goethite, in another locality with chrysocolla, Plancheite, Dioptase and Atacamit.

There are only known to a small number of localities. In addition to the type locality in Bisbee was found Paramelaconit in the Algomah mine in the U.S. state of Michigan, Skouriotissa in Cyprus, Laurion in Greece and Budleigh Salterton in Devon (England )

Crystal structure

Paramelaconit crystallizes in the tetragonal crystal system in space group I41/amd with the lattice parameters a = 5.837 Å and c = 9.932 Å and four formula units per unit cell.