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, silica (silicon dioxide, ) is usually consid ...

mineral and a member of the

zeolite Zeolites are microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a metal ion or H+. These pos ...

family. It is one of the rarer zeolites. It was named for Richard Barrer, 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 lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a r ...

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 ( ; it, Sardegna, label=Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label=Algherese and Catalan) is the second-largest island in the Mediterranean Sea, after ...

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 of la ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

, and a few other localities.

References

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