TAB. CCXXXITI. 
CALX sulphata. 
Sulphate of Lime, or Gypsum. 
Class 2. Earths. Order 1. Homogeneous. 
Gen. 3. Lime. Spec. 3. Sulphate of Lime. 
SE 
Gyesum, when crystallized on an amorphous gangue, is. 
not very generally known, and has been very Iittle noticed 
by authors; common Selenites only have been placed 
among the crystallized varieties*. 
The present specimen is from Derbyshire, where largish 
blocks or lumps of amorphous Gypsum are found, often very 
white, looking like fine Carrara Marble, and sold for va- 
rious purposes, as making what some cal] Alabaster figures, 
turned candlesticks, imitations of fruit, &c.+ When the 
workmen are cutting it, they frequently find hollows in- 
cluding the crystals; but these do not often come into the 
hands of the curious. ‘The white face of the hollow has 
often a snowy appearance, and is finely grained, upon 
which the pellucid crystals look sometimes very beautiful. 
The crystals are generally more clear and delicate than the 
Selenite, not having clay among them; and this is all the 
difference between them, since they are liable to the same 
forms of crystals, which are composed of opposite trape- 
* Crystallized Selenites—see tal. 67, are said to want a little Carbonate 
of Lime to make plaister, but the other varieties have naturally a sufficiency. 
+ The less solid pieces serve, when burnt, for casting plaister figures, and 
for inferior purposes. 
VOL. Ill. B 
