210 
DESCRIPTIVE MINERALOGY. 
ORDER II. STRONTIA. 
This order includes the following : 
1. Celestine. 2. Strontianite. 3. Barystrontianite. 
CELESTINE. 
[In allusion to the sky-blue colour which it sometimes possesses.] 
Strontiane Sulfatee. Jlauj. — Sulphate of Strontian. Clcaveland, Phillips and Thomson. — Prismatoidal Baryte. 
Jameson. — Prisrnatoidischer Hal-Baryte. Mohs. — Celestine. Beudant, Shepard and Dana. 
Description. Colour usually white, but sometimes blue, red or 
yellowish red. It occurs regularly crystallized; also massive, 
fibrous, radiated, stalactitic, etc. The primary form is a right 
rhombic prism. Fig. 47. M on M 104° (Phillips); 104° 48' 
(Hauy); 104° 30 7 (Beudant.) Cleavage perfect parallel with the 
sides of the primary, less so parallel with the base. Fracture 
uneven. Lustre vitreous, inclining to pearly. Varies from trans¬ 
parent to opaque. Hardness from 3.0 to 3.5. Specific gravity 
from 3.60 to 4.00. Before the blowpipe, it behaves very nearly 
like heavy spar, except that it communicates a red tinge to the flame. 
Composition. Sulphuric acid 43.64, strontia 56.36 (Beudant). Formula SrO.S0 3 . But 
it usually contains various foreign substances in small proportions. 
Geological Situation. In this State, celestine is usually associated with limestone, but 
it does not seem to be peculiar to any geological epoch. It also accompanies gypsum, but it 
has not been found here in the red sandstone and trap, as it is in various parts of England. 
localities. 
Cayuga County. In the rounded masses of dark coloured limestone which are found in 
the slate on the Owasco outlet near Auburn, thin blades of this mineral, in the form of radii, 
are not uncommon. It is usually white, and is associated with crystallized calcareous spar. 
Herkimer County. Fibrous celestine, of a bluish grey or blue colour, and closely resem¬ 
bling some foreign specimens, occurs on the farm of James Crill, in the western part of the 
town of Stark, where it is associated with gypsum. Imperfect crystalline terminations are 
also found intermixed with these fibres, which have a high lustre, and are transparent. The 
same variety has also been observed in thin seams in the slate in a small water course near 
Stephen Hammond’s, and not far from the old road to Fairfield. It is often mixed in various 
proportions with carbonate of lime.* 
Fig. 47. 
Vanuxem. Ncw-York Geological Reports, 1840. 
