Mineral Factbook

Riebeckite

܆Na2(Fe2+3Fe3+2)Si8O22(OH)2IMA symbol: Rbkredefined

Riebeckite is a silicate mineral with the formula ܆Na2(Fe2+3Fe3+2)Si8O22(OH)2, crystallizing in the monoclinic system. It has a Mohs hardness of 6, typically black in color, with a vitreous luster, a specific gravity of 3.433-5. Cleavage is perfect.

Photos

Riebeckite specimen photo
Robertwhyteus · Public domain · Commons
Riebeckite specimen photo
Fernando Losada Rodríguez · CC BY-SA 4.0 · Commons
Riebeckite specimen photo
Tõnis Saadre · CC BY-SA 4.0 · Commons
Riebeckite specimen photo
James St. John · CC BY 2.0 · Commons

Physical properties

Hardness (Mohs)
6single sourceWikidata (CC0)
Specific gravity
3.433-5 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892)
Color
blackDana, System of Mineralogy, 6th ed. (1892)
Luster
vitreousDana, System of Mineralogy, 6th ed. (1892)
Cleavage
perfectDana, System of Mineralogy, 6th ed. (1892)

Classification

Nickel-Strunz (10th)9.DE.25Wikidata (CC0)
Nickel-Strunz (9th)9.DE.25Wikidata (CC0)