joaquinite-(Ce), benitoite : Dallas Gem Mine (Benitoite Mine ; Benitoite Gem Mine ; Gem Mine), Dallas Gem Mine area, San Benito River headwaters area, New Idria District, Diablo Range, San Benito Co., California, USA — Photo: Géry PARENT · Public domain
Joaquinite-(Ce)
Joaquinite-(Ce) is a rare silicate mineral with the chemical formula NaBa2Ce2Fe2+Ti2Si8O26(OH)·2H2O. It crystallizes in the monoclinic system with orthorhombic pseudomorphism and exhibits tabular crystals.
Intro adapted from Wikipedia (CC BY-SA).
Joaquinite-(Ce) is an IMA-recognized mineral species in the silicate class, with the chemical formula NaBa₂Fe²⁺Ti₂Ce₂(Si₄O₁₂)₂O₂(OH)·H₂O.
It crystallizes in the monoclinic crystal system (space group C2). It is a member of the Joaquinite structural group.
Key properties: Mohs hardness 5.5; specific gravity 3.89–3.98; Vitreous luster; optically biaxial.
IMA symbol Jq-Ce, IMA status: approved, named in 1909.
Found in a natrolite vein cutting a glaucophane schist inclusion in a serpentinite body (San Benito Co., California, USA); in fenitized gneisses and alkalic syenites (Seal Lake, Canada).
It is found associated with Orthojoaquinite-(Ce), benitoite, neptunite, natrolite (San Benito Co., California, USA); aegirine, barylite, eudidymite, neptunite (Seal Lake, Canada).
The name refers to Joaquin Ridge, near the original locality at the Gem mine, California, USA.