Celestine (the IMA-accepted name) or celestite is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

consisting of strontium sulfate ( Sr S O). The mineral is named for its occasional delicate blue

color Color ( American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are ass ...

. Celestine and the

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

mineral

strontianite Strontianite ( Sr C O3) is an important raw material for the extraction of strontium. It is a rare carbonate mineral and one of only a few strontium minerals. It is a member of the aragonite group. Aragonite group members: aragonite (CaCO3), ...

are the principal sources of the element

strontium Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is ex ...

, commonly used in

fireworks Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large number of devices in ...

and in various metal alloys.

Etymology

Celestine derives its name from the

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

word ''caelestis'' meaning celestial which in turn is derived from the Latin word ''caelum'' meaning sky or heaven.

Occurrence

Celestine occurs as

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macr ...

s, and also in compact massive and fibrous forms. It is mostly found in

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

rocks, often associated with the minerals

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywa ...

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

, and

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...

. On occasion in some localities, it may also be found with

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

inclusions. The mineral is found worldwide, usually in small quantities. Pale blue crystal specimens are found in

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Afric ...

. White and orange variants also occurred at

Yate Yate is a town and civil parish in South Gloucestershire, England. It lies just to the southwest of the Cotswold Hills and is northeast of Bristol city centre and from the centre of Bath, with regular rail services to Bristol and Gloucest ...

Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

, UK, where it was extracted for commercial purposes until April 1991. The skeletons of the

protozoan Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histor ...

'' Acantharea'' are made of celestine, unlike those of other radiolarians which are made of

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

. In carbonate marine sediments, burial dissolution is a recognised mechanism of celestine precipitation. It is sometimes used as a gemstone. Celestine Poland.jpg, Celestine from the Machow Mine, Poland Celestine SrSO4.jpg, Celestine mineral on display at

Yale Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the worl ...

's Peabody Museum

Geodes

Celestine crystals are found in some geodes. The world's largest known

geode A geode (; ) is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the fill ...

, a celestine geode in diameter at its widest point, is located near the village of

Put-in-Bay, Ohio Put-in-Bay is a village located on South Bass Island in Put-in-Bay Township, Ottawa County, Ohio, United States, east of Toledo. The population was 154 at the 2020 census. The village is a popular summer resort and recreational destinati ...

, on

South Bass Island South Bass Island is a small island in western Lake Erie, and a part of Ottawa County, Ohio, Ottawa County, Ohio, United States. It is the southernmost of the three Bass Islands and located 3 miles (4.6 km) from the south shore of Lake Erie ...

Lake Erie Lake Erie ( "eerie") is the fourth largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also h ...

. The geode has been converted into a viewing cave, Crystal Cave, with the crystals which once composed the floor of the geode removed. The geode has celestine crystals as wide as across, estimated to weigh up to each. Celestine geodes are understood to form by replacement of

alabaster Alabaster is a mineral or rock that is soft, often used for carving, and is processed for plaster powder. Archaeologists and the stone processing industry use the word differently from geologists. The former use it in a wider sense that include ...

nodules consisting of the calcium sulfates

Calcium sulfate Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris, ...

is sparingly soluble, but strontium sulfate is mostly insoluble. Strontium-bearing solutions that come into contact with calcium sulfate nodules dissolve the calcium away, leaving a cavity. The strontium is immediately precipitated as celestine, with the crystals growing into the newly-formed cavity. Celestitemadagascar.jpg, Celestine geode section Crystal Cave Ohio.JPG, Inside the Crystal Cave geode in Ohio

Footnotes

References

External links