White crystals of the very rare mineral jaffeite from the type locality in Kombat mine, Namibia, associated to minoritary brown defernite. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Jaffeite
A hydrated calcium silicate of high-temperature metamorphosed limestones.
Intro adapted from Wikipedia (CC BY-SA).
Jaffeite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₆Si₂O₇(OH)₆.
It crystallizes in the hexagonal crystal system (space group P3).
Key properties: specific gravity 2.65; White streak; Vitreous luster; optically uniaxial.
IMA symbol Jaf, IMA status: approved, named in 1987.
Closely in association with or enclosed by defernite within low-grade metamorphic rocks.
It is found associated with Defernite, hausmannite, apatite, brucite, hillebrandite, vesuvianite, glaucochroite, galena, copper.
In honor of Professor Howard W. Jaffe of the University of Massachusetts, Amherst, Massachusetts, USA.