Journal of Mineralogical and Petrological Sciences
Online ISSN : 1349-3825
Print ISSN : 1345-6296
ISSN-L : 1345-6296
LETTERS
Talmessite from the Uriya deposit at the Kiura mining area, Oita Prefecture, Japan
Masayuki OHNISHINorimasa SHIMOBAYASHIShigetomo KISHIMitsuo TANABEShoichi KOBAYASHI
Author information
JOURNALS FREE ACCESS

2013 Volume 108 Issue 2 Pages 116-120

Details
Abstract

Talmessite was found in veinlets (approximately 1 mm wide) cutting into massive limonite in the oxidized zone of the Uriya deposit, Kiura mining area, Oita Prefecture, Japan. It occurs as aggregates of granular crystals up to 10 μm in diameter and as botryoidal aggregates up to 0.5 mm in diameter, in association with arseniosiderite, and aragonite. The talmessite is white to colorless, transparent, and has a vitreous luster. The unit-cell parameters refined from powder X-ray diffraction patterns are a = 5.905(3), b = 6.989(3), c = 5.567(4) Å, α = 96.99(3), β = 108.97(4), γ = 108.15(4)°, and Z = 1. Electron microprobe analyses gave the empirical formula Ca2.15(Mg0.84Mn0.05Zn0.02Fe0.01Co0.01Ni0.01)∑0.94(AsO4)1.91·2H2O on the basis of total cations = 5 apfu (water content calculated as 2 H2O pfu). It is suggested that the talmessite formed as a secondary mineral derived from löllingite, calcite, and diopside.

Information related to the author
© 2013 Japan Association of Mineralogical Sciences
Previous article
feedback
Top