Selenite is a transparent and colorless (or very lightly colored) variety of Gypsum that forms in distinct crystals. The name 'Selenite' is mostly synonymous with Gypsum but has been used historically to describe the transparent variety, as opposed to Satin Spar Gypsum for the fibrous variety and Alabaster for the fine-grained massive …

Modified date: 06/03/2024. Selenite is a beautiful and versatile mineral that belongs to the gypsum mineral family. It is composed of hydrous calcium sulfate and is known for its transparent to translucent appearance. Selenite crystals often exhibit a pearly or glass-like luster and have a unique fibrous or columnar structure.

Satin Spar Gypsum: A fibrous variety of Gypsum. See also the main page on Satin Spar. Selenite: The name 'selenite' is mostly synonymous with gypsum but has been used historically to describe the transparent variety, as opposed to satin spar gypsum for the fibrous variety and alabaster for the fine-grained massive form. The original name was ...

Selenite is a common name for the mineral gypsum. Historically it was only used for transparent crystals and the white fibrous variety was called satin spar instead. (Since the latter was also used for fibrous calcite and aragonite, scientific sources use the name as a prefix instead. This material is labeled satin spar gypsum.)

Satin Spar is commonly referred to as "fibrous gypsum" because of its long and thin fibrous crystal formation. This gives it a silky, satin-like luster, from where it gets its name. Selenite typically forms in large, transparent, tabular crystals with …

The micritized, microbial laminae may also form a lateral, straight-sided, bridge connecting the crests of adjacent swallowtail crystals. Such bridges overlie a primary, intercrystalline cavity enclosed between adjacent gypsum crystals, and overlain with clastic gypsum and radial growth of fine, fibrous and swallowtail gypsum crystals …

1. Introduction. Gypsum (CaSO 4 ·2H 2 O) accounts for approximately 20% of the minerals in giant salt deposits formed via the evaporation of seawater throughout Earth's history (Zharkov, 1981, Warren, 2006).Its ionic components SO 4 2− and Ca 2+ are the fourth and fifth most abundant dissolved ions of seawater (Stumm and Morgan, …

The fibrous gypsum crystals in our samples show optical continuity and constant width in growth direction, suggesting that growth of fibrous gypsum crystals is more likely to be a continuous process. In crack-seal theory by Ramsay (1980), antitaxial fibrous vein growth occurs in vein-wall interface due to low cohesion, and is driven by …

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate (CaSO4·2H2O). It is commonly found in sedimentary rock formations and is often …

An ~1 mm zone of elongate, fibrous gypsum is present at the contact between the gypsum and the siltstone with the fibers growing with the growth generally perpendicular to the contact (Fig. 5).

Selenite is a colorless variety of gypsum, occurring as transparent crystals or foliae. Satin spar is a finely fibrous variety filling veins in massive gypsum or other rocks. Properties of Anhydrite. Anhydrite (CaSO 4) has a specific gravity of 2.93 and a hardness of 3 to 3.5. It is commonly white, but a grayish, bluish, or reddish tinge may ...

Gypsum is a mineral so versatile that it can look like glass, feel like silk, or even blossom in the desert like a flower. ... Because of its fibrous nature, it can also be carved into beautiful shapes and objects, making it a popular choice for artisan crafts and decorative items. ... This happens because the gypsum crystals grow in a way that ...

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 … See more

Other articles where gypsum flower is discussed: cave: Depositional materials and features: …of fibrous crystals known as gypsum flowers. Because of their higher solubility, sulfate minerals either do not occur or are destroyed in damp or wet caves.

This special shine comes from its fibrous crystal structure, which scatters light in a way that makes it look almost like it's glowing from within. As a type of gypsum, …

Gypsum outcrop in Clark County. Gypsum is an evaporite because it precipitates (settles) out of water as the water evaporates. the three varieties of gypsum are selenite, satin spar, and rock gypsum. Selenite, found throughout the Red Hills, has flat, diamond-shaped crystals that can be split into thin sheets.Satin spar is white or pink and fibrous with a …

Varieties of gypsum. Selenite: This is what most people consider to be real, natural selenite. It forms in large, transparent slabs that flake easily; Golden healer selenite: Normal selenite with iron inclusions …

Acicular, fibrous, reniform, or granular crystals are also common. Structure and Composition Although in principal a complete solid solution exists between celestite (SrSO 4) ... Typical gypsum crystals are tabular (like the ones seen in Figure 14.414, above), thick to thin, often forming as elongated sheaves or masses.

Scale: Specimen size 5 cm. © Dave Barthelmy. Gypsum Crystallography. Axial Ratios: a:b:c =0.3741:1:0.4143. Cell Dimensions: a = 5.68, b = 15.18, c = 6.29, Z = 4; beta = …

Origin of fibrous gypsum in the Newark rift basin, eastern North America. John K Warren Mohamed El Tabakh. 1998, Journal of Sedimentary Research ...

The chemical formula for gypsum is CaSO 4.2H 2 O (calcium sulfate dihydrate). Gypsum forms typical monoclinic crystals. Most often, it forms in perfect tabular crystals, but it can also appear as acicular (long and thin) crystals in large bundles, rosettes, grainy or scaly crystals, fibrous veins, and lenticular crystals.

Gypsum Supergroup. Name: First known mention is by Theophrastus about 300-325 BCE from the Greek γυψοζ (gypsos) meaning plaster. Isostructural with: Ardealite, Brushite, Pharmacolite. The most common sulphate mineral. Found as both massive material, including the alabaster variety; and clear crystals, the selenite variety; and, parallel ...

Gypsum crystals can take on spectacular forms, from the translucent, blade-like selenite to the fibrous, satin spar variety. It's a common evaporite mineral, forming when saline waters evaporate.

The name Gypsum comes from the Greek word gypsos, which means plaster and mentions of the minerals are known beginning approximately 300 BC. Around the globe, gypsum forms in massive chunks, clear crystals, and as fibrous bundles. Gypsum is a soft mineral and was chosen as an example mineral by Friedrich Mohs for …

Crystals and fibrous masses may be curved, sometimes severely, forming formations that are sometimes called "Rams Horns". Crystals frequently twin, forming perfect fishtail …

Secondary breakage occurs on fibrous crystals between 400 and 700 °C. Lattice distortion of gypsum crystals also occurs, which is mainly manifested in the transformation of crystals from fibrous or acicular to powder. This is because an increase in temperature directly leads to an increase in thermal cracking.

Gypsum is found as twinned monoclinic crystals, called Selenite, or silky fibrous crystals, called Satin spar. Massive blocks of fine-grain white, translucent gypsum are called Alabaster and have been …

Gypsum crystals may form in curved shapes that resemble the horns of a ram. "Ram's horn" selenite crystal, 9.7 x 8.2 x 4.6 cm, Guangdong Province, ... Lapidaries could cut cabochons and carvings of almost size desired from massive gypsum. Fibrous material could yield large carvings up to several pounds. Faceted selenites could reach hundreds …

Prismatic, columnar, bladed, acicular/needle-like, or fibrous—rod-shaped crystals, including, tourmaline (acicular prisms), gypsum and calcite (columnar), topaz, rutile and amphibole ... Cleavage can be perfect (mica—in 1 direction, calcite—in 3 directions), good (gypsum), indistinct/poor (apatite, chalcopyrite), or a mineral may have …

Additionally selenite, the most popular form of gypsum, can form as fibrous silky crystals called "satin spar". Gypsum can even form as fine grained crystals called alabaster which is commonly used in ornamental applications, or carvings, due to its soft and translucent nature.

In sediments of the Kamchatka hot springs, we observed prismatic, prismatic pseudo-hexagonal, fibrous, tubular, lenticular and twinned gypsum crystals, with crystal sizes ranging from <200 nm to ...

Satin Spar is a fibrous variety of Gypsum which is often confused with Selenite because they share the same compound formula with a very similar appearance. Many Selenite specimens on the market are actually Satin Spar crystals, yet there are a few ways you can tell the difference. Satin Spar is fibrous and appears in a milky-white shade ...

Fibrous Speleothems. These formations are composed of aggregates of crystals that are fibrous or filament-like in nature. Most typically they are gypsum, but can be composed of a variety of other mineral salts like epsomite or halite. In form, they are generally classified into four subtypes: hair, cotton, rope, and snow.

The gypsum crystals making up the vein fill grew perpendicular to the fracture walls, suggesting that opening and filling of the fractures was contemporaneous and that the fractures are ...

Definition of fibrous structure. i. If the crystals in a mineral aggregate are greatly elongated and have a relatively small cross section, the structure or texture is fibrous. The fibers may be parallel, as in crocidolite and sometimes in gypsum and cerussite. When the fibers are very fine, they may impart a silky luster to the aggregate, as ...

Fibrous gypsum crystals formed as a result of recrystallization of . synthetic gypsum in 15% sulfuric acid at temperature 80 o C. 332 CWB-6/2010. W konsekwencji, ...

Gypsum Flowers. Flowers are speleothems with crystal petals radiating from a central point. The petals are fibrous or prismatic crystals growing in a parallel orientation. They are usually made of sulfate minerals such as gypsum or epsomite, but can form from halite, or rarer (for caves) minerals, and even ice.