Imayoshiite, Ca3Al(CO3)[B(OH)4](OH)6·12H2O, a new mineral of the ettringite group from Ise City, Mie Prefecture, Japan. (2nd January 2018)

• Record Type: Journal Article
• Authors: Nishio-Hamane, D.; Ohnishi, M.; Momma, K.; Shimobayashi, N.; Miyawaki, R.; Minakawa, T.; Inaba, S.
• Is Part Of: Mineralogical magazine. Volume 79:Number 2(2015:Apr.)
• Page Start: 413
• Page End: 423
• Publication Date: 2018-01-02
• Subjects: imayoshiite, -- new mineral, -- ettringite group, -- crystal structure, -- Ise, -- Mie Prefecture; Mineralogy -- Periodicals; Mineralogy -- Great Britain -- Periodicals; 549.05
• DOI: 10.1180/minmag.2015.079.2.18
• Languages: English
• ISSNs: 0026-461X

Abstract

Abstract: Imayoshiite, Ca3 Al(CO3 )[B(OH)4 ](OH)6 ·12H2 O, occurs in cavities in the altered gabbro xenolith in the sepentinized dunite exposed at Suisho-dani, Ise City, Mie Prefecture, Japan. Imayoshiite is colourless and transparent with a vitreous lustre and its aggregates are white with a silky lustre. Imayoshiite has a white streak. Its Mohs hardness is 2–3. It is brittle, the cleavage is distinct on {100} and the fracture is uneven. The mineral is uniaxial (–) with the indices of refraction ω = 1.497(2) and ε = 1.470(2) in white light. Imayoshiite is hexagonal, P 63, a = 11.0264(11), c = 10.6052(16) Å by powder diffraction and a = 11.04592(2), c = 10.61502(19) Å by single-crystal diffraction. The structural refinement converged to R 1 = 2.35%. Imayoshiite is the first member of the ettringite group with both CO3 and B(OH)4 anions.