Celestite
Celestine · Mineral Specimen
Crystal System
Orthorhombic system, typically forming tabular or prismatic crystals, often found as crystal clusters lining geodes.
Mineral Group
Sulfates
Chemical Formula
SrSO4
Formation Process
Sedimentary environments, typically precipitating from evaporating marine basins and sabkhas, or hydrothermally in cavities within sedimentary rocks such as limestone and sandstone.
About This Crystal
The specimen is a classic geode cluster featuring pale to medium sky-blue tabular crystals with a vitreous to pearly luster. The crystals are transparent to translucent and line the interior cavity of a rounded, greyish-white sedimentary matrix.
Physical Characteristics
Color ranges from colorless to pale blue; streak is white; perfect cleavage in three directions forming rhombic blocks; fracture is uneven; specific gravity is approximately 3.95; tenacity is brittle; shows weak fluorescence under UV light.
Optical Properties
Biaxial (+) with refractive indices of nalpha = 1.622, nbeta = 1.624, ngamma = 1.631; strong double refraction; weak pleochroism in colored varieties.
Hardness & Durability
Origin Region
Madagascar is the most famous source for high-quality blue crystal clusters. Other notable deposits include Sakoany in Madagascar, Italy, the United Kingdom, and the United States (Ohio and New York).
Hardness & Durability
Mohs hardness of 3 to 3.5, making it very soft and easily scratched. Perfect cleavage makes it fragile and prone to splitting upon impact. Poor wearability for jewelry.
Care & Maintenance
Do not clean with water or harsh chemicals as it is slightly soluble in water; avoid exposure to direct sunlight for extended periods to prevent color fading; store away from harder stones to avoid scratching.
Rarity & Value
Commonly available as mineral specimens. Value depends on color saturation, crystal size, clarity, and overall aesthetic arrangement. Prices range widely from affordable small geodes to expensive collector pieces.
Special Characteristics
Famous for its delicate sky-blue coloration caused by natural irradiation and trace impurities. Often exhibits thermoluminescence.
Lore & History
Discovered in the late 18th century, celestite derives its name from the Latin word 'caelestis' meaning celestial, due to its sky-blue color. In metaphysical lore, it is considered a stone of divine connection, peace, and angelic communication, traditionally associated with the throat and third-eye chakras.