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Minerals A-E
Celestite
Name
Celestite
Chemistry
SrSO4, Strontium Sulfate
Uses
As a specimen and ore of strontium
Color
Usually blue but can also be colorless or yellow.
Hardness
3 - 3.5
Specific gravity
3.9 heavy
Crystals
It crystallize in the orthorhombic system. The crystals are tabular or prismatic and resembles barite
Accompanied by:
Barite, gypsum, halite, anhydrate, calcite, dolomite, fluorite.
Fracture
Uneven
Luster
Vitreous
Cleavage
Basal, perfect: Prismatic, good.
Streak
White
Similar to:
Barite
Celestite, strontium sulfate forms tabular or prismatic crystals (orthorhombic system), nodules, and granular or fibrous cleavable masses. Hardness is 3-31/2, streak and color white, luster vitreous, and specific gravity 3.9.
Celestite is usually found disseminated through limestone or sandstone and also occurs in evaporites, hydrothermal veins, and metallic ore deposits, especially lead.
The name comes from the word celestial, which means heavenly. Celestite is a favorite among mineral collectors. Its sky blue (or celestial) color is very pretty, and is unique in the mineral kingdom.
Celestite also forms with other colorful minerals, making very nice combinations. Blue celestite with bright yellow sulfur is one of the most famous colorful combinations of minerals.
Celestite has the same structure as Barite (BaSO4), and forms very similar crystals. The two may seem identical by ordinary methods, but a flame test can distinguish them. By scraping the dust of the crystals into a gas flame, the color of the flame will confirm the identity of the crystal. If the flame is a pale green, it is barite, but if the flame is red, it is celestite. The flame test works because the elements barium (Ba) and strontium (Sr) react with the flame and produce those colors.
Normally barite is not blue, but many specimens of blue barite are often misidentified as celestite. The nice crystals, good luster and attractive blue color make fine specimens of celestite an outstanding mineral for someone's cabinet or display case
