Billwiseite is a very rare oxide mineral found at the pegmatite commonly referred to as "Stak Nala" located within a few hundred yards from the village of Toghla in the Stak Nala, Gilgit-Baltistan, Pakistan. It has only been found as a coating on a single crystal of lepidolite. The sole rock containing Billwiseite is kept at the Royal Ontario Museum, catalogue number M5595.
{{Infobox mineral | name = Billwiseite | category = Oxide minerals | image = | imagesize = | caption = | formula = (Sb3+)5(Nb,Ta)3WO18 | IMAsymbol=Bwi | strunz = 4.DX | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = C2/c | unit cell = a = 54.206(6) Å, b = 4.9163(5) Å, c = 5.5540(6) Å; β = 90.396(2)°; Z = 4 | color = Pale yellow (with a tinge of green) | habit = | twinning = | cleavage = {100} Indistinct | fracture = Hackly | mohs = 5 | luster = Vitreous | refractive = unknown | opticalprop = | birefringence = | pleochroism = | streak = Colorless, very pale yellow | gravity = 6.33 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = | references = }}
Billwiseite is a very rare oxide mineral found at the pegmatite commonly referred to as "Stak Nala" located within a few hundred yards from the village of Toghla in the Stak Nala, Gilgit-Baltistan, Pakistan. It has only been found as a coating on a single crystal of lepidolite. The sole rock containing Billwiseite is kept at the Royal Ontario Museum, catalogue number M5595.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).