72 
Derams.—Celestine, 1815. W. Philips. Outlines of 
Mineralogy and Geology (1818). 
In this mineral, strontian, combined with sulphuric acid, 
has obtained the name of celestine (celestis, celestial) from its © 
delicate tint of light blue. 
Celestite is a word altered by Dana, from Celestine, and is 
a native sulphate of strontian (SrO. SO3.) The word Celestite 
appears to be superseding the older form, Celestine, and since 
it has been adopted in the mineralogical collection of the 
British Museum, Kensington, we employ it here; for Dana 
justly remarks that words terminating in ine are chemical, and 
should be restricted to the science of chemistry. 
The tint of Celestite is generally of a cool blue, but this is 
not invariably the case: often it is colourless; frequently 
reddish; or again of a yellowish hue, which is sometimes varied 
by a charming iridescence, or glancing play of light. Touching 
the blue crystals, Wittstein finds that the colour is due to a 
trace of phosphate of iron ; whilst Mr Stoddart, of Bristol, could 
not discover it in the pale blue crystals from Clifton. This may 
be explained by the fact that the Jena Celestite analysed by 
Wittstein is of a peculiarly dark blue fibrous kind. Neither 
strontium nor its oxide is met with in nature: the two minerals 
having that metal as its base are the carbonate of strontium 
(Strontianite) and the sulphate of strontium (Celestite). Stron- 
tianite occurs principally in Saxony and Westphalia in veins 
in cretaceous strata, now mined on the large scale as a 
source of caustic strontia, which is used for recovering sugar 
from molasses in refining. Celestite occurs normally in modi- 
fied rhombic crystals, not infrequently flattened or tabular, 
also in long prismatic needles, more especially in specimens 
from Sicily—and in fibrous or massive varieties; but rarely in 
a granular form. Further on we shall refer to some erratic 
forms peculiar to the celestites of the sulphur deposits of 
Sicily. 
Disrrisurion.—In the South of England the mineral in 
question is but little known; say on the other side of Bristol, 
though it has been reported from Weston-super-Mare and 
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