Celestite (strontium sulfate) has a sky (or celestial) blue color that is unique in the mineral kingdom. The name stems from the Latin word Caelertis, meaning "of the sky." Popular lore says that celestite came from the star group called the Pleiades, and that it holds the wisdom of the ages.
This ethereal mineral is believed to aid personal creative expression, help reduce stress, and provide peace of mind. It is also said to help one adjust to higher states of awareness, provide access to and transfer of information from the angelic realms, and assist in clairaudient endeavors.
First found in Italy in the 18th century, celestite crystals have since been unearthed in New York, Michigan, Ohio, Colorado, California, Poland, Czechoslovakia, Germany, and Mexico. A nodular form, like a geode with an exterior of sedimentary rock and a cavity full of brilliant crystals, is found in India. The finest specimens of any type are from Madagascar.
Celestite has the same structure as barite (BaSO4), and forms very similar crystals. While barite is not typically blue, occasional blue specimens are usually misidentified as celestite. The two may seem identical by ordinary methods, but a flame test can distinguish them. Scrape some dust from the crystals into a flame -- if the flame turns a pale green, it is barite; but if the flame is red, it is celestite.
The red shown in the flame test is due to the presence of strontium, an alkaline earth metal. Strontium compounds are important components in signal flares, tracer ammunition, and fireworks (because of the red flame), color television picture tubes and computer monitors (it absorbs x-rays and improves the brilliance of glass), and in making permanent ceramic magnets and refining zinc and beet sugar.
Due to its extreme reactivity with air (it will ignite spontaneously when finely powdered), strontium is always found in combination with other elements in minerals like celestite and strontianite, and celestite is its primary source.
Metaphysically, Celestite is believed to aid in personal creative expression, helps to reduce stress, and provides peace of mind. It is also said to help one adjust to higher states of awareness, provide access to and transfer of information from the angelic realms, and assist in clairaudient endeavors.
Celestite (a.k.a. Celestine): SrSO4, strontium sulfate
Color: Usually blue, but may also be colorless or yellow and contain tints of red, green, and brown.
Habit: Generally well-developed tabular or bladed crystals; also nodular, fibrous, or granular.
Mohs scale hardness: 3 - 3.5
Transparency: Crystals are transparent to translucent.
Cleavage: Perfect in one direction, less so in another direction.
Specific gravity: 3.9+ (above average for translucent minerals)
Other: Red color in flame test; some specimens fluoresce under UV light, may fade if exposed to direct sunlight.