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gypsum, common sulfate mineral of great commercial importance, composed of hydrated calcium sulfate (CaSO4·2H2O). In well-developed crystals the mineral commonly has been called selenite. Gypsum also occurs disseminated in limestones, dolomitic limestones, and some shales.
What is gypsum and how is it made?
Gypsum, also known as calcium sulfate hydrate, is a naturally occurring mineral found in layers of sedimentary rock all over the world. It is formed by the evaporation and replenishment of waters containing calcium and sulfates.
What’s gypsum made from?
Gypsum is composed of calcium sulphate (CaSO4) and water (H2O). Its chemical name is calcium sulphate dihydrate (CaSO4. 2H2O). Gypsum can be milled mixed with water and then resume its original rock-like state.
How do we get gypsum?
Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface exposures. It is often associated with the minerals halite and sulfur.
Is gypsum a salt?
Gypsum is the neutral salt of a strong acid and strong base and does not increase or decrease acidity. Dissolving gypsum in water or soil results in the following reaction: CaSO4·2H2O = Ca2+ + SO42- + 2H2O.
Is gypsum a rock or mineral?
Gypsum is one of the more common minerals in sedimentary environments. It is a major rock forming mineral that produces massive beds, usually from precipitation out of highly saline waters.
What is pure gypsum?
Pure gypsum is a white rock but sometimes impurities colour it grey, brown or pink. Its scientific name is calcium sulphate dihydrate and its chemical formula is CaSO42H2O. This means that, for every molecule of gypsum, there are two molecules of water. This is a most important fact in the gypsum story.
Is gypsum harmful to humans?
If handled improperly, gypsum can cause irritation to the skin, eyes, mucous membranes and the upper respiratory system. Symptoms of irritation can include nosebleeds, rhinorrhea (discharge of thin mucous), coughing and sneezing. If ingested, gypsum can clog the gastrointestinal tract.
Are gypsum and selenite the same?
Gypsum and Selenite have the same chemical composition but differ in crystallisation habit. Selenite is usually crystalline and the association of the impurities is superficial which are eliminated by washing. Gypsum is fine grained in nature and is beneficiated by flotation only.
Where is gypsum found in nature?
Gypsum deposits occur in many countries, but Spain, Thailand, the United States, Turkey, and Russia are among the leading producers. The largest gypsum crystal was found in the Braden mine in Chile and exceeds 3 metres (about 10 feet) in length and 0.4 metre (about 1.5 feet) in diameter.
What rocks contain gypsum?
Gypsum can be found as thick layers in shale and as attractive crystals. No gypsum deposits are 100% pure. It is usually found with deposits of a combination of the following: limestone, sand, shale, anhydrite and sometimes rock salt.
Is gypsum a crystal?
Gypsum is a mineral found in crystal as well as masses called gypsum rock. It is a very soft mineral and it can form very pretty, and sometimes extremely large colored crystals. Massive gypsum rock forms within layers of sedimentary rock, typically found in thick beds or layers.
Are gypsum and lime the same?
 Lime is a carbonate, hydroxide or oxide of calcium whereas gypsum is a sulphate. 2. Lime has more alkaline properties whereas gypsum is slightly more acid. Because of its alkalinity, lime raises pH of soils while gypsum does not raise pH of soils.
Why is gypsum good for soil?
Gypsum helps soil better absorb water and reduces erosion. It also cuts down on phosphorus movement from soils to lakes and streams and improves the quality of various fruits and vegetables, among other benefits.”Feb 6, 2019.
Is gypsum a calcium carbonate?
Gypsum is calcium sulfate, and lime is calcium carbonate. Both are soil amendments, and both provide calcium. Only gypsum provides a source of sulfur.
Does gypsum dissolve in water?
Gypsum is somewhat soluble in water, but more than 100 times more soluble than limestone in neutral pH soils. When applied to soil, its solubility depends on several factors, including particle size, soil moisture, and soil properties. Some soils benefit from application of gypsum as a source of Ca.
What is another name for gypsum?
n. Calcium Sulphate, calcium sulfate, mineral.
Is gypsum a flower?
Sometimes the mineral crystals grow as large curved fibrous bundles having the appearance of flower petals as well as other shapes. The most common of the sulfate minerals is gypsum, CaSO4·2H2O and the commonly appearing speleothems are known as gypsum flowers.
Is gypsum an organic fertilizer?
Naturally mined gypsum is considered an allowed non-synthetic input for crop use according to National Organic Program (NOP) regulations. Natural gypsum is also listed generically as acceptable in the Organic Materials Review Institute (OMRI) handbook.
How do you identify gypsum?
Gypsum is readily identified by its softness (a fingernail scratches it). Gypsum comes as clear crystals that display one perfect cleavage (selenite), as blocks of featureless white rock (alabaster), and as silky fibrous blocks (satin spar).
What happens when gypsum is heated to 100 C?
Gypsum is calcium sulphate dihydrate (CaSO4. When gypsum is heated to a temperature of 100⁰C (373K), it loses three-fourths of its water of crystallisation and forms plaster of Paris (CaSO4.
