Wairakite

Wairakite is a zeolite mineral with an analcime structure but containing a calcium ion. The chemical composition is Ca₈(Al₁₆Si₃₂O₉₆)•16H₂O. It is named for the location of its discovery in Wairakei, North Island, New Zealand, by Czechoslovakian mineralogist Alfred Steiner in 1955.^[4][5] The first finds were in hydrothermally altered rhyolitic tuffs, ignimbrites and volcaniclastic rocks.^[5] The mineral has since been found in metamorphic rocks and in geothermal areas. It was most likely first successfully synthesized in a laboratory in 1970.^[6]

Wairakite
Wairakite from Azerbaijan
General
Category	Tectosilicate minerals, zeolite group
Formula	Ca8(Al16Si32O96)•16H2O
IMA symbol	Wrk[1]
Strunz classification	9.GB.05
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	I2/a
Unit cell	a = 13.69 Å, b = 13.64 Å c = 13.56 Å; β = 90.51°; Z = 8
Identification
Color	colorless to white
Luster	vitreous, dull
Streak	white
Diaphaneity	transparent, translucent
References	[2][3]