C. U. Shepard—Mineralogical Notices. 401 
the specimens received, is the monetite which sometimes forms 
isolated yas deme 08 the size of one’s hand. The second con- 
stituent of the masses is a snow-white gypsite, either crystal- 
lized, fibrous or polveralent; while the remaining one is calcite, 
in wel -formed, semi- bpanecieay — No alumina or oxide 
of iron is present in the aggreg 
The monetite, besides ate in thick isolated masses as 
above mentioned, also forms irregular seams through the gyp- 
shaped cavities. More rarely, it presents itself in botryoidal 
shapes, with rough crystalline Alors But under all circum- 
stances, it is an highly crystalline mineral. 
Mineralogical description.—- Primary oe * right oblique angled 
prism z on T about 148° as determined approximately by 
the ¢ on siniieiater Secondary forms, terminal and acute 
fateral edict replaced by single planes, the former generally 
very narrow. Height of prisms less than one-third their longest 
breadth ; ee much less. Greatest length of crystals 
between qeth and y4th of an inch. They exhibit numerous 
irregular enna indentations, but are without striz or curva- 
tures. They cross and interpenetrate each other in several 
directions, some of the groups suggesting a regular composition 
of individuals. Though exhibiting Boy Schaal rifts, the cleavage 
is indeterminate. Fracture, uneven. Luster, vitreous. Semi- 
Gravity =2°75, which is a little below the actual, from the 
impossibility of wholly clearing the crystals of the mealy white 
monite and gypsite by which they are more or less coated. 
Before the blowpipe, heated in a glass tube, ite white and 
evolves Suonidie. ut unattende odor. In latinum 
oe turns white and melts into a globule with ‘aepeallinn 
face 
pages tee 
I Mean. 
Lim a 92 40°59 40°255 
Proiphoris acid 225.2525 4641 49°79 47-100 
ee POMS ES ES 7°20 1°90 4°550 
Ware oo a 8-474 7°88 8-175 
100-00 100°16 100°080 
4:55 per wg Sagar hcies acid calls for 3-185 per cent lime 
and 2°047 per cent wa thus constituting 9°782 per cent of 
gypsite. The sainiern si 0-2 per cent of moisture on drying 
it several ee at nearly 100° C. Subtracting the above con- 
stituents we 
* See also the note on the crystalline form by E. 8. ee oe Pe 405, 
+ The water in the first analysis was estimated by differe 
