Apophyllite

Apophyllite

Infobox mineral
name = Apophyllite
category =
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boxbgcolor =



caption =
formula = (K,Na)Ca4Si8 O20(F,OH) • 8H2O
molweight =
color = Usually white, colorless; also blue, green, brown, yellow, pink, violet
habit = prismatic, tabular, massive
system = Tetragonal; Orthorhombic (natroapophyllite)
twinning =
cleavage = [001] Perfect
fracture = Uneven
mohs = 4.5 - 5
luster = Vitreous; Pearly
refractive = 1.536
opticalprop =
birefringence =
pleochroism = Dichroic (colorless)
streak = White
gravity = 2.3 - 2.4
melt =
fusibility =
diagnostic =
solubility =
diaphaneity = Transparent to translucent
other =

The name apophyllite refers to a specific group of phyllosilicates, a class of minerals that also includes the micas. Originally, the group name referred to a specific mineral, but was redefined in 1978 to stand for a class of minerals of similar chemical makeup that comprise a solid solution series, and includes the members fluorapophyllite, hydroxyapophyllite, and natroapophyllite. The name apophyllite is derived from the Greek "apophylliso," meaning "it flakes off," a reference to this class's tendency flake apart when heated, due to water loss. These minerals are typically found as secondary minerals in holes in basalt or other igneous rocks. They can also be called "fisheye stone". [http://www.maden.hacettepe.edu.tr/dmmrt/dmmrt50.html#d1040]

Though relatively unfamiliar to the general public, apophyllites are fairly prevalent around the world, with specimens coming from some of the world's most well-known mineral localities. These localities include: Poona, India; the Harz Mountains of Germany, Mont Saint-Hilaire in Canada, and Kongsberg, Norway, with other locations in Scotland, Ireland, Brazil, Japan, and throughout the United States.

Uses

Apophyllites are popular as collector's minerals. This popularity is due to a combination of factors, including their abundance, color variety, and well-defined crystals. Naturally forming pyramidal structures, they refract light in obvious rainbows, and can form "natural pyramids" when subjected to rock tumbling.

pecies of Apophyllite

*Fluorapophyllite, (potassium, sodium)calcium4silicon8oxygen20(fluorine, hydroxide)hydrate|8 - white, colorless, yellow, green, violet
*Hydroxyapophyllite, potassiumcalcium4silicon8oxygen20(hydroxide, fluorine)hydrate|8 - white, colorless
*Natroapophyllite, (potassium, sodium)calcium4silicon8oxygen20fluorinehydrate|8 - brown, yellow, colorless

References

* [http://webmineral.com/data/Apophyllite.shtml WebMineral Listing]
* [http://www.mindat.org/min-283.html MinDat Listing]
* [http://mineral.galleries.com/minerals/silicate/apophyll/apophyll.htm Mineral Galleries]
*cite journal | author= Colville AA, Anderson CP, Black PM| title= Refinement of the crystal structure of apophyllite: I. X-ray diffraction and physical properties | journal=American Mineralogist| year=1971 | volume=56 | pages=1222–1233


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Look at other dictionaries:

  • Apophyllite — Catégorie IX : silicates[1] apophyllite, Rio grande do sul, Brésil (28x14cm) …   Wikipédia en Français

  • APOPHYLLITE — L’apophyllite est un phyllosilicate. Cristallisant dans le système quadratique, ses cristaux se présentent sous la forme de prismes carrés, courts, tronqués, avec clivage basal à éclat nacré. C’est un minéral de couleur blanc, rose, jaune pâle ou …   Encyclopédie Universelle

  • Apophyllite — A*poph yl*lite, n. [Pref. apo + Gr. ? leaf; so called from its foliated structure or easy cleavage.] (Min.) A mineral relating to the zeolites, usually occurring in square prisms or octahedrons with pearly luster on the cleavage surface. It is a… …   The Collaborative International Dictionary of English

  • apophyllite — [ə päf′ə līt΄] n. [< APO + Gr phyllon, a leaf + ITE1: so named from its flaking off under the blowpipe] a semihard, hydrous, tetragonal mineral, KCa4Si8O20 (F,OH)·8H2O, usually found as variously colored crystals or flat, sheetlike plates …   English World dictionary

  • apophyllite — /euh pof euh luyt , ap euh fil uyt/, n. a hydrous potassium and calcium silicate mineral occurring in white crystals. [1800 10; APO + PHYLL + ITE1] * * * ▪ mineral       potassium calcium fluoride silicate mineral that is related structurally to… …   Universalium

  • apophyllite — apofilitas statusas T sritis chemija formulė KCa₄[(OH,F)|(Si₄O₁₀)₂]·8H₂O atitikmenys: angl. apophyllite rus. апофиллит …   Chemijos terminų aiškinamasis žodynas

  • apophyllite — noun Etymology: French, from apo + Greek phyllon leaf more at blade Date: 1810 a mineral composed of a hydrous silicate of potassium, calcium, and fluorine that is related to the zeolites and is usually found in transparent square prisms or white …   New Collegiate Dictionary

  • apophyllite — noun Any of several forms of a pale pink or green mineral being a mixed fluoride and silicate of potassium and calcium …   Wiktionary

  • apophyllite — ap·o·phyl·lite …   English syllables

  • apophyllite — a•poph•yl•lite [[t]əˈpɒf əˌlaɪt, ˌæp əˈfɪl aɪt[/t]] n. mir a hydrous potassium and calcium silicate mineral occurring in transparent crystals • Etymology: 1800–10 …   From formal English to slang

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