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Gypsum satin spar mineral - Nov 14, 2022 · Satin Spar. Satin Spar is a fibrous shape of Gypsum. It is typically

ⓘ Gypsum var. Satin Spar Gypsum: CaSO 4 · 2H 2 O: S ⓘ Gypsum var. Alabaster:

Gypsum also occurs in crystal form, with the two most common varieties being large clear crystals that are often termed selenite, and fibrous crystals, known as satin spar. ‘Selenite’ is the Greek word for moon, and refers to the crystals well-developed pearl-like luster that can reflect a soft moon-like glow. Gypsum – Satin Spar. £ 2.07 – £ 5.54 ex VAT. Gypsum satin spar mineral specimens from Morocco, which are a pearly white colour composed of high quality fibrous crystals which are long and orientated in the same direction giving the samples a silky lustre. These pieces are available in various optional sizes, supplied in a card tray with a ... Gypsum also occurs in crystal form, with the two most common varieties being large clear crystals that are often termed selenite, and fibrous crystals, known as satin spar. …Dec 16, 2022 · Sandylite, satin spar, and rock gypsum are the three main types of gypsum. The crystals of sylrite are flat and diamond-shaped, and they can be sliced into thin sheets from the Red Hills. The satin spar has a silky luster and is white or pink in color. Aside from its versatility, gypsum is useful for a variety of purposes. Feb 13, 2012 - This Pin was discovered by Matthew Keyes. Discover (and save!) your own Pins on Pinterest.There are many differences between selenite and calcite. Selenite is in the gypsum family of minerals and has a Mohs hardness of about two. Calcite can be found existing in other rocks and has a Mohs hardness score of about three. Furthermore, the chemical makeup of calcite is CaCO3, and it has an absolute hardness of fourteen.Mineral Study Kit, 15 specimens. $19.95. This complete mineral kit has number-coded, 1" specimens of 15 important minerals so students can handle, test, and learn all about them. Includes an identification key, a description of each mineral specimen & more! quantity.Check out our satin spar minerals selection for the very best in unique or custom, handmade pieces from our rocks & geodes shops.Jan 22, 2021 · Sometimes known as the lucky stone, satin spar brings good fortune to the bearer. It is a powerful calming stone that helps to clear confusion and brings clarity to the mind. It is also a great stone to work with for regulating hormones and anything menstrual cycle related. Satin Spar commonly mistaken as selenite, satin spar are fibrous ... Jan 22, 2020 · Selenite is the crystalline form of gypsum. These crystals are very brittle and fragile. Selenite can form large crystals—some as big as bicycle tires! Visitors to the park can see selenite crystals on hikes to Lake Lucero. There are three other varieties of the mineral gypsum: satin spar, desert rose, and gypsum flower. Satin spar variety of gypsum Silky lustre. Silky minerals have a parallel arrangement of extremely fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos, ulexite and the satin spar variety of gypsum. A fibrous lustre is …Satin spar selenite gypsum has a beautiful white color and can also appear colorless. The luster is silky to pearly and sometimes vitreous (glassy). The mineral feels soft and smooth to the touch. Selenite has a white streak and is very soft. You can use your fingernail to scratch the sample. At just a 2 on the Mohs hardness scale, your ...1.9" SATIN SPAR GYPSUM Crystal - Raw Natural Mineral - Rough Specimen - Healing Crystal - Meditation Stone - Collectable - From Arkansas 62g (1.3k) ... Huge Satin Spar Gypsum Crystal Slab 542 Gram True Natural Gypsum Crystal Satin Spar Crystal Orange Satin Spar Gypsum Crystal +free CrystalsGypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. [4] It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. [5] [6] [7] [8] Gypsum also crystallizes as translucent crystals of selenite. Satin Spar vs Selenite. Selenite and satin spar are both varieties of gypsum minerals. No, they are not the same. However, the satin spar is also known as a lucky stone, which aids in dealing with infertility and brings good luck. How to Use Selenite. Selenite crystal comes in different shapes and varieties like a wand, tower, stick, plate, …Fine grained, compact variety of Gypsum (hydrated calcium sulfate), usually white or pale colored and translucent. Alabaster is soft and can be scratched slightly with a fingernail. It also dissolves slowly in wet environments. Alabaster was used since ancient times in the Iran, Pakistan, Egypt, Greece, Algeria, Tunisia, and Italy for ...Satin spar | mineral | Britannica. Login. Subscribe. Home Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture Money Videos. Satin spar, massive (noncrystalline) variety of the mineral gypsum.Selenite (also known as Satin Spar), while functioning as an energetic healing tool, is, in the simplest terms, a transparent variety of Gypsum. It’s comprised of the crystallisation of the calcium sulphate mineral. Selenite is typically sold as masses of granular, tabular, and prismatic shards. What makes it so incredibly special is the fact …Formula: CaSO4 · 2H2O A variety of Gypsum A fibrous variety of Gypsum. See also the main page on Satin Spar. Unique Identifiers Hide Mindat ID: 8574 (as Satin Spar Gypsum) 1784 (as Gypsum) Long-form identifier: 1:1:8574:4 (as Satin Spar Gypsum) 1:1:1784:4 (as Gypsum) GUID ( UUID V4 ): 904aef34-7d19-434a-ac60-bdfd9918aad1 (as Satin Spar Gypsum)Depending on the formation conditions calcium sulfate minerals can adopt a wide variety of crystal habits/morphologies, and textures (Fig. 2).Gypsum usually appears as well-formed (highly) transparent single and twinned crystals (i.e. selenite, Fig. 2 a), and as polycrystalline semi-opaque aggregates with randomly (alabaster) or parallel (satin spar) oriented crystals (Fig. 2 b).Satin Spar: Satin Spar is a fibrous variety of selenite characterized by its silky and satin-like appearance. It often exhibits a fibrous texture with parallel or radiating fibers that give it a silky sheen. ... Selenite is primarily associated with evaporite environments, where saline water evaporates and deposits gypsum minerals. It is commonly found in …Silky Gypsum (Satin Spar), Luster produced by internal reflections Tremolite from threadlike fibers within the mineral. Minerals with directional cleavage which results in a fiber-like habit often have this luster. Adamantine Cinnabar, Diamond A hard, brilliant luster like that of a diamond. This occurs in minerals withSelenite, satin spar, desert roses, and gypsum flowers are four varieties of the mineral gypsum; all show obvious crystalline structure. The four crystalline varieties of gypsum are sometimes grouped together and called “selenite”. The dirty diamonds are of the crystalline variety. Collecting SpotsGypsum also occurs in crystal form, with the two most common varieties being large clear crystals that are often termed selenite, and fibrous crystals, known as satin spar. …Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate (CaSO4·2H2O). It is commonly found in sedimentary rock formations and is often associated with other minerals such as anhydrite, halite, and sulfur. The name “gypsum” is derived from the Greek word “gypsos,” which means “plaster” or “chalk.”.Selenite Selenite, satin spar, desert rose, and gypsum flower are four varieties of the mineral gypsum; all four varieties show obvious crystalline ...Varieties: There are four crystalline varieties of gypsum, which are satin spar, desert rose, gypsum flower, and selenite, all of which can sometimes be grouped ...The Uses of Selenite and Satin Spar. Gypsum, as a mineral, has many uses and can be found in plaster, shampoos, creams, and even some tofu. Selenite has even been used to form window panes, as demonstrated at the Santa Sabina church in Rome. However, today, many people know selenite and satin spar for their attested metaphysical properties. From the Greek, gyps meaning "burned" mineral. Selenite from the Greek in allusion to its pearly luster (moon light) on cleavage fragments. Name Pronunciation: Gypsum : Synonym: Alabaster : ICSD 2057 : PDF 33-311 : Satin Spar : Selenite : Gypsum Image: Images:Gypsum (CaSO 4 *2H 2 O) is a soft, water soluble mineral that is processed to make critical building materials especially wallboard. Gypsum is mostly massive (Fig. 1A) but also forms silky satin spar (Fig. 1B). It is sometimes mixed with the related mineral, anhydrite (Fig. 1C). Gypsum was deposited from ancient sea water that evaporated during ... Here are some of gypsum’s interesting physical and chemical properties. Color: Colorless to white but may appear with shades of pink, tan, yellow, blue, brown, red and gray from the presence of impurities in the mineral. Hardness: 2 on Mohs Hardness Scale. Crystal Shape: Thick tabular to lenticular crystals.Layered Satin Spar Gypsum: This variety of Satin Spar refers to specimens where the crystals have formed distinct layers. Use Layered Satin Spar Gypsum for dream recall. Fishtail Satin Spar Gypsum: Fishtail Satin Spar Gypsum has distinctive twinned crystals that grow outward. Use this variety to set intentions for personal change and growth. The Uses of Selenite and Satin Spar. Gypsum, as a mineral, has many uses and can be found in plaster, shampoos, creams, and even some tofu. Selenite has even been used to form window panes, as demonstrated at the Santa Sabina church in Rome. However, today, many people know selenite and satin spar for their attested metaphysical properties. Both minerals are very light, but ulexite is somewhat less dense; reference works give a specific gravity ranging from 1.6 to 1.96. Gypsum is heavier, with a specific gravity ranging from 2.2 to 2.32. With the aid of Lew Brubacher and Mike Chong of the Department of Chemistry at the University of Waterloo, we took a picture of ulexite floating ...Layered Satin Spar Gypsum: This variety of Satin Spar refers to specimens where the crystals have formed distinct layers. Use Layered Satin Spar Gypsum for dream recall. Fishtail Satin Spar Gypsum: Fishtail Satin Spar Gypsum has distinctive twinned crystals that grow outward. Use this variety to set intentions for personal change and growth.Gypsum is an hydrous calcium sulfate CaSO4·2H2O and an abundant mineral worldwide. Aside from the colourless crystals of selenite, other varieties include satin spar which is translucent, opalescent white with a fibrous structure. Alabaster is the fine-grained, opaque form of gypsum appreciated for carving and ornamental use.Varieties: There are four crystalline varieties of gypsum, which are satin spar, desert rose, gypsum flower, and selenite, all of which can sometimes be grouped ...In modern usage Satin Spar is a compact fibrous variety of Gypsum. It is generally white, silky and translucent with pearly or milky appearance.From the Greek, gyps meaning "burned" mineral. Selenite from the Greek in allusion to its pearly luster (moon light) on cleavage fragments. Name Pronunciation: Gypsum : Synonym: Alabaster : ICSD 2057 : PDF 33-311 : Satin Spar : Selenite : Gypsum Image: Images: Gypsum (CaSO 4 *2H 2 O) is a soft, water soluble mineral that is processed to make critical building materials especially wallboard. Gypsum is mostly massive (Fig. 1A) but also forms silky satin spar (Fig. 1B). It is sometimes mixed with the related mineral, anhydrite (Fig. 1C). Gypsum was deposited from ancient sea water that evaporated during ...Gypsum, satin spar, white fibrous; 3-4cm pieces, 10/PK. Qty: Add to Cart. Product Description. Details. High quality, trimmed mineral and rock specimens that ...Name Origin: From the Greek, gyps meaning "burned" mineral. Selenite from the Greek in allusion to its pearly luster (moon light) on cleavage fragments. Name Pronunciation: Gypsum Synonym: Alabaster ICSD 2057 PDF 33-311 Satin Spar Selenite Gypsum Image Images: Gypsum Comments: Bladed rosettes of gypsum. Location: unknown. Scale: Specimen size 6 cm.Selenite is the crystalline form of gypsum. These crystals are very brittle and fragile. Selenite can form large crystals—some as big as bicycle tires! Visitors to the park can see selenite crystals on hikes to Lake Lucero. There are three other varieties of the mineral gypsum: satin spar, desert rose, and gypsum flower.Selenite Meanings, Zodiacs, Planets, Elements, Colors, Chakras, and more. Science & Origin of SeleniteSelenite is a calcium sulfate mineral that is the crystallized transparent variety of Gypsum. Satin Spar is the silky and fibrous variety of Gypsum that is abundant and commonly mislabeled as Selenite. Both of these can be found crystallized in the form of masses, acicular, granular, tabular ...A fibrous variety of Gypsum. See also the main page on Satin Spar.Fine grained, compact variety of Gypsum (hydrated calcium sulfate), usually white or pale colored and translucent. Alabaster is soft and can be scratched slightly with a fingernail. It also dissolves slowly in wet environments. Alabaster was used since ancient times in the Iran, Pakistan, Egypt, Greece, Algeria, Tunisia, and Italy for ...A particular type of gypsum. Formula: CaSO4.H2O Hardness: 2 Description: A sulfate mineral with a monoclinic crystal system and a pearly lustre. Specimen n...Selenite is a type of gypsum. Believe it or not, it has a very similar chemical composition to drywall! Drywall, alabaster, desert rose, gypsum flower, satin spar, and selenite crystals are all made up of calcium sulfate dihydrate. Despite the name, none of these contain the element selenium. They vary based on where and how they form.Genuine Selenite Gypsum Satin Spar Rough Gemstone 9g Raw Crystal Healing Stone Chakra Stone Natural Gemstone Ad vertisement by TheKubesStore. TheKubesStore. 4.5 out of 5 stars (78) ... Gypsum Mineral Charging Plate for Cleansing / Clearing, Protection Ritual Ad vertisement by OccultMinerals. OccultMinerals. 5 out of 5 stars (6)Satin Spar and Selenite are believed to have different healing properties. Satin Spar is said to be calming and soothing, making it helpful for meditation and stress relief. Selenite is said to promote mental clarity, enhance intuition, and provide protection from negative energy. Both minerals are commonly used in crystal healing and can be ... Fluorescent gypsum satin spar mineral specimens from Morocco. Samples fluoresce a pale blue to purple colour when under shortwave UV light. These pieces are supplied in a 2" x 2" card tray with a label. Ideal for collectors of fluorescent minerals.Selenite, satin spar, desert rose, gypsum flower are crystal habit varieties of the mineral gypsum. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO4·2H2O. Selenite contains no significant selenium – The similar names both derive …Availability. Selenite and Satin Spar are probably the two most mixed up crystals in the entire metaphysical world, despite actually being two forms of the same mineral. This article will help you to tell the difference between Selenite and Satin Spar.From the Greek, gyps meaning "burned" mineral. Selenite from the Greek in allusion to its pearly luster (moon light) on cleavage fragments. Name Pronunciation: Gypsum : Synonym: Alabaster : ICSD 2057 : PDF 33-311 : Satin Spar : Selenite : Gypsum Image: Images:S.Manish Impex - Offering Gypsum Satin Spar in Sowcarpet, Chennai, Tamil Nadu. Read about company. Get contact details and address | ID: 11368114788.This month will be mostly Sunny. The average daily high/low will be 71°F/56°F. The expected highest/lowest temperature is 84°F/50°F. There will be 2 rainy days. Calendar.Selenite is closely related to the other crystalline forms of Gypsum: Satin Spar, a compact fibrous variety that is generally translucent with a pearly chatoyant appearance; Desert Rose, most often bladed in the familiar shape of a rose with an outer druse of sand, or with sand throughout; and Gypsum Flower, an opaque variety usually attached ...Gypsum (satin spar) Mineral Type: Cleavage - A nonmetallic mineral that is white or colorless, has 2 cleavage planes (one is good and the other is poor), is fibrous in appearance, and has a hardness of 2 (can be scratched with your finger nail). Click on image to see enlarged photo.Gypsum's hardness is about 2, and usually it cannot be accepted as a gemstone, but Satin spar with the same composition and hardness, due to the cat eye or chatoyancy phenomenon (More than 150 cm ...Gypsum - satin-spar. Mineral Color: white, gray, pearly Streak: Layers: Texture: fibers Shiny: satiny metallic luster Hardness: Moh's scale 2. Hematite. ... If rocks are buried deep in the Earth at high temperatures and pressures, they form new minerals and textures all without melting. If melting occurs, magma is formed, starting the rock ...Satin Spar is a variety of Gypsum that is very often mislabelled as Selenite. It is very closely related, as they have the same chemical composition, but they have crystallised in a different way. Satin Spar forms in white, fibrous masses, and is often carved into hearts, eggs, spheres, bowls and mountain shapes, whereas Selenite forms in large clear plates which are very rarely polished ... The petrographic examination of this facies reveals the presence of large crystals of gypsum, both platy (selenite) and fibrous (satin-spar) forms that have been recognized by the presence of their crystalline form, tabular to prismatic habit, moderate relief, subhedral to euhedral shape, two set of perfect and mutually perpendicular …White Gypsum Satin Spar. Collection. John Betts - Fine Minerals. Description. Compact mass of parallel, fibrous Gypsum crystals known as Satin Spar. Ex. John A. Manley ca. 1890s. Locality. Savoie, France. Dimensions. 6 x 4 x 2 cm.Gypsum Satin Spar. Collection. Hershel Friedman. Description. A fibrous vein of Gypsum Satin Spar with a lovely peachy-orange color. Locality. Unknown. Dimensions. 4.5 x 2.8 x 2.0 cm. Satin spar is a fibrous gypsum with silky luster. Alabaster is the fine-grained massive variety. Selenite is a variety which yields broad colorless and transparent cleavage folia . Chemical Properties. Chemical Properties; Gypsum Physical Properties; Gypsum Optical Properties; Occurrence and Formation of Gypsum; ... Gypsum is a valuable …Gypsum (CaSO 4 *2H 2 O) is a soft, water soluble mineral that is processed to make critical building materials especially wallboard. Gypsum is mostly massive (Fig. 1A) but also forms silky satin spar (Fig. 1B). It is sometimes mixed with the related mineral, anhydrite (Fig. 1C). Gypsum was deposited from ancient sea water that evaporated during ...Satin spar Most often silky and fibrous; [9] chatoyant; can exhibit some coloration [10] The satin spar name has also been applied to fibrous calcite (a related calcium mineral), which can be distinguished from gypsum by its greater hardness (Mohs 3), rhombohedral cleavage, and reaction with dilute hydrochloric acid. [11] Desert roseCheck out our satin spar mineral selection for the very best in unique or custom, handmade pieces from our shops.As mentioned above, Selenite or Satin Spar is a crystallized form of Gypsum. Gypsum is a very soft sulfate mineral made of calcium sulfate dihydrate with a pearly luster. While Satin Spar’s technical geologic luster is described as “silky”. Usually mined in Morocco or Mexico, some varieties are found in Canada.Calcium sulfate appears as odorless, white powder or colorless, crystalline solid. Crystals sometimes have a blue, gray or reddish tinge or can be brick red. Density: 2.96 g cm-3. Calcium sulfate is a calcium salt and an inorganic calcium salt. Anhydrite is a mineral with formula of CaS 6+ O 4 or Ca (SO 4 ).Gypsum (CaSO 4 *2H 2 O) is a soft, water soluble mineral that is processed to make critical building materials especially wallboard. Gypsum is mostly massive (Fig. 1A) but also forms silky satin spar (Fig. 1B). It is sometimes mixed with the related mineral, anhydrite (Fig. 1C). Gypsum was deposited from ancient sea water that evaporated during ...Selenite, satin spar, desert rose, gypsum flower are crystal habit varieties of the mineral gypsum. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO4·2H2O. Selenite contains no significant selenium – The similar names both derive …ⓘ Gypsum var. Satin Spar Gypsum: CaSO 4 · 2H 2 O: S ⓘ Gypsum var. Alabaster: CaSO 4 · 2H 2 O: Ca: Calcium; Ca ⓘ Anhydrite: CaSO 4: Ca ⓘ Dolomite: CaMg(CO 3) 2: Ca ⓘ Gypsum: CaSO 4 · 2H 2 O: Ca ⓘ Gypsum var. Satin Spar Gypsum: CaSO 4 · 2H 2 O: Ca ⓘ Gypsum var. Alabaster: CaSO 4 · 2H 2 O: Sr: Strontium; Sr ⓘ Celestine: SrSO 49 thg 9, 2023 ... ... gypsum a significant mineral resource worldwide. Name: From the Greek ... Satin spar is a fibrous gypsum with silky luster. Alabaster is the ...Selenite, satin spar, desert rose, gypsum flower are crystal habit varieties of the mineral gypsum.Satin spar is an adjective used when the fibrous habit of a mineral gives it a satin luster. The term satin spar has been used in the past to describe calcite and aragonite; however, it is currently accepted as one variety of the mineral gypsum, along with selenite and alabaster.Selenite Selenite, satin spar, desert rose, and gypsum flower are four varieties of the mineral gypsum; all four varieties show obvious crystalline ...Gypsum Satin Spar. Collection. Hershel Friedman. Description. A fibrous vein of Gypsum Satin Spar with a lovely peachy-orange color. Locality. Unknown. Dimensions. 4.5 x 2.8 x 2.0 cm.Feb 13, 2023 · Gypsum (satin spar) Mineral Type: Cleavage – A nonmetallic mineral that is white or colorless, has 2 cleavage planes (one is good and the other is poor), is fibrous in appearance, and has a hardness of 2 (can be scratched with your finger nail). Click on image to see enlarged photo. Gyprex Satinspar 600mm is a suspended ceiling tile, available in both black and white, that's easy to install and clean. The tile's surface is stain resistant and easy to wipe so that ceilings stay looking pristine. Its high light reflectance and smooth satin finish make it perfect for creating light, bright interiors in environments from ...gypsum crystals bluish anhydrite with calcite. Anhydrite and Gypsum. Indiana's Evaporite Minerals satin spar gypsum. Page 2. 611 North Walnut Grove Ave ...Satin Spar (Gypsum) (Satin Spar). Satin Spar (Gypsum) is a variety of gypsum that is usually fibrous and forms prismatic crystals. Unlike selenite, it usually has a white color to …Satin Spar is a variety of Gypsum that is very often mislabelled as Selenite. It is very closely related, as they have the same chemical composition, but they have crystallised in a different way. Satin Spar forms in white, fibrous masses, and is often carved into hearts, eggs, spheres, bowls and mountain shapes, whereas Selenite forms in large clear plates which are very rarely polished ...Varieties: There are four crystalline varieties of gypsum, which are satin spar, desert rose, gypsum flower, and selenite, all of which can sometimes be grouped together forming selenite. Mineral Group: Gypsum is part of the sulfate group, which is a group of minerals that consist one or more metallic elements and the sulfate ion (SO42-). All ...White Fibrous Gypsum: Selenite Satin Spar - 10 Pieces of Mineral - Rock Specimen - Measures 1 - 2 inches on Longest Side (11.1k) $ 26.95. Add to Favorites ... Selenite Bar-Satin Spar Gypsum-Selenite Crystal Plate-Healing Crystal-Wholesale Bulk Crystal-Crystal Set Holder-Selenite Stick HolderSatin spar variety of gypsum Silky lustre. Silky minerals have a parallel arrangement of extremely fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos, ulexite and the satin spar variety of gypsum. A fibrous lustre is …Localities for Satin Spar Gypsum Hide. This map shows a selection of localities that have lati, Selenite, satin spar, desert rose, gypsum flower are crystal habit varieties of the mineral gypsum. All varieties of gyp, Selenite (also called satin spar, desert rose, or gypsum flower) is a crystal form of the miner, Availability. Selenite and Satin Spar are probably the two most mixed up crystals, Back to Rocks and Minerals Articles Kelly Snyder and Peter Russell Gypsum, hydrated calcium sulphate, C, I consider selenite and satin spar to be accepted varietal names for the mineral Gypsu, Satin spar | mineral | Britannica. Login. Subscribe. Home Quizzes & Games History & Society Science & T, Satin Spar. Satin Spar is a fibrous shape of Gypsum. It is typical, 4 thg 9, 2020 ... My Collection: EVAPORATE MINERALS (Halite, Gyps, Armstrong Bioguard Plain Tegular (BP2223M) 600 x 600mm Reveal Edge (24, My Collection: EVAPORATE MINERALS (Halite, Gypsum, Selen, Gypsum is the mineral that includes in its structure Sulfate , variety of gypsum is called satin spar . Anhydrite (CaSO 4) is a calc, As mentioned above, Selenite or Satin Spar is a crystallized fo, Alabaster is a common name used for particularly pure deposits o, From the Greek, gyps meaning "burned" mineral. Seleni, Formula: CaSO4 · 2H2O A variety of Gypsum A fibrous variety of, Four crystalline varieties comprise gypsum including.