Chibaite is a rare silicate mineral. It is a silica clathrate with formula (n = 3/17 (max)). The mineral is cubic (diploidal class, m) and the silica hosts or traps various hydrocarbon molecules, such as methane, ethane, propane and isobutane.Chibaite on Mindat.org
Chibaite was first described for specimens collected from Arakawa, Minamibōsō, Chiba Prefecture, Honshu Island, Japan. The mineral was approved by the IMA in 2009.
References
Gatta, C. B., Chibaite, American Mineralogist, New Mineral Names, Volume 97, pp 2064–2072, 2012