Barrerite is a

tectosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dio ...

mineral and a member of the

zeolite Zeolites are a group of several microporous, crystalline aluminosilicate minerals commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a meta ...

family. It is one of the rarer zeolites. It was named for

Richard Barrer Richard Maling Barrer FRS (16 June 1910 – 12 September 1996) was a New Zealand-born chemist. His areas of research included gas permeability of membranes and zeolite science, of which he was a founding figure; he also gave his name to the zeo ...

, a New Zealand-born chemist. Barrerite crystal are white to pinkish, with a vitreous-glassy luster. The crystal system is

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic Lattice (group), lattices result from stretching a cubic crystal system, cubic lattice along two of its orthogonal pairs by two different factors, res ...

and is flat and tabular in appearance. It has a Mohs hardness of 3 to 4 and its cleavage is perfect. Barrerite has a white streak and a density of 2.13. It was first described in 1974 for an occurrence in

Sardinia Sardinia ( ; ; ) is the Mediterranean islands#By area, second-largest island in the Mediterranean Sea, after Sicily, and one of the Regions of Italy, twenty regions of Italy. It is located west of the Italian Peninsula, north of Tunisia an ...

at Sant' Efisio Tower on Cape Pula in Cagliari Province. It has also been reported from Rocky Pass,

Kuiu Island Kuiu Island is an island in the Alexander Archipelago in southeastern Alaska. It lies between Kupreanof Island, to its east, and Baranof Island, to its west. The island is long, and wide. It is nearly cut in two by Affleck Canal. It has o ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

, and a few other localities.

References

Zeolites Orthorhombic minerals Minerals in space group 63 {{silicate-mineral-stub