XANTHOCONITE
XANTHOCONITE Xanthoconite – Ag3AsS3 – is a very rare sulfosalt, classified in the Proustite Group, since it is the monoclinic dimorph of proustite. The xanthoconite-proustite transition occurs at 180-202°C. Not to be confused with “xanthochroite” = CdS ! 1. Characteristics Crystal system: Monoclinic prismatic. Color: Red-orange, yellow-orange, red-brown, brown […]
XENOTIME
XENOTIME “Xenotime” – Y(PO4) and Yb(PO4) – is a term used for both xenotime-(Y) and xenotime-(Yb), but xenotime-(Yb) is extremely rare, so the mineral species usually referred to is xenotime-(Y). Xenotime-(Y) is a rare phosphate, used as an ore for yttrium and heavy REEs, especially dysprosium. Occasionally it is cut as a gemstone. Xenotime-(Y) is […]