hemihydrate (was: extinction6)

[Tetanurae@aol.com]

jedimr_thomas@hotmail.com wrote:
<<I guess not, 'cause anhydrite is greek for "without water", and my 
Mineralogy-syllabus sais:
Gipsum: CaSO4.2H2O
Hemihydrate: CaSO4.1/2H2O
Anhydrite: CaSO4
of course this might be wrong nobody's perfect, but it seems logical>>

According to the Webmineral website, the mineral your professor is refering 
to is known as Bassanite, 2(CaSO4)·(H2O), which essentially the same formula 
listed by your instructor:

http://www.webmineral.com/data/Bassanite.shtml

There is no entry for Hemihydrate or anything close to that in its spelling.

Pete Buchholz
tetanurae@aol.com