Chibaite

{{Short description|Rare silicate mineral}}

{{Infobox mineral

| name = Chibaite

| boxwidth =

| boxbgcolor =

| image = Chibaite & Bosoite.jpg

| imagesize =

| alt =

| caption = White crystals of the rare silica-hydrocarbon minerals chibaite (IMA 2008-067) and bosoite (IMA 2014-023) from the type and only known locality worldwide for both species: Arakawa, Minamiboso City, Chiba Prefecture, Honshu Island, Japan.

| struct image =

| struct caption =

| struct imagesize =

| struct2 image =

| struct2 caption =

| struct2 imagesize=

| SMILES =

| Jmol =

| category =

| formula = SiO₂•n(CH₄, C₂H₆, C₃H₈, i-C₄H₁₀) (n ≤ 3/17)

| IMAsymbol=Cib{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}

| molweight =

| strunz = 4.DA

| dana =

| system = Isometric

| class =

| symmetry = F2/d{{overbar|3}}

| unit cell = a = 19.3742 V=7,272.29 ų

| colour = white

| habit =

| twinning =

| cleavage =

| fracture =

| tenacity =

| toughness =

| mohs = 7

| luster = Vitreous

| streak =

| diaphaneity =

| gravity = 1.933

| density =

| polish =

| opticalprop = isotropic

| refractive = 1.470

| birefringence =

| pleochroism =

| 2V =

| dispersion =

| extinction =

| length fast/slow =

| fluorescence =

| absorption =

| melt =

| Curie temp =

| fusibility =

| diagnostic =

| solubility =

| impurities =

| alteration =

| other =

| prop1 =

| prop1text =

| references =

| var1 =

| var1text =

| var2 =

| var2text =

| var3 =

| var3text =

| var4 =

| var4text =

| var5 =

| var5text =

| var6 =

| var6text =

}}

Chibaite is a rare silicate mineral. It is a silica clathrate with formula {{chem|Si|O|2|•n(CH|4|,C|2|H|6|,C|3|H|8|,i-C|4|H|10|)|}} (n = 3/17 (max)). The mineral is cubic (diploidal class, m{{overline|3}}) and the silica hosts or traps various hydrocarbon molecules, such as methane, ethane, propane and isobutane.[http://www.mindat.org/min-39335.html Chibaite] on Mindat.org{{Cite web |url=http://www.elementsmagazine.org/archives/e8_3/e8_3_sn_jams.pdf |title=The Discovery of Chibaite, Elements, June 2012, section: Japan Association of Mineralogical Sciences p. 230 |access-date=2014-03-19 |archive-date=2021-01-19 |archive-url=https://web.archive.org/web/20210119203430/http://www.elementsmagazine.org/archives/e8_3/e8_3_sn_jams.pdf |url-status=dead }}

Chibaite was first described for specimens collected from Arakawa, Minamibōsō, Chiba Prefecture, Honshu Island, Japan. The mineral was approved by the IMA in 2009.