Thorite var. Thorogummite on Ferrian Annite — Suishoyama Pegmatite, Iizaka Village, Fukushima Prefecture, Japan

A well-documented specimen of thorite (variety thorogummite) from one of Japan's most mineralogically significant pegmatites. The Suishoyama pegmatite — a vertical, pipe-shaped intrusion roughly 60 meters in diameter near Iizaka Village, Kawamata, in Fukushima Prefecture — was originally worked commercially for feldspar and quartz for the ceramic industry, but is far better known among mineralogists as an unusually yttrium-rich locality: it's the type locality for both iwashiroite-(Y) and, more recently, miyawakiite-(Y), and has produced a notably diverse rare-earth and thorium mineral suite.

This specimen shows yellow-brown thorogummite crystals — a hydrous, thorium-dominant member of the thorite group — hosted in ferrian annite, an iron-rich mica. Thorogummite forms through the partial hydration and alteration of primary thorite, and its presence here reflects the broader thorium- and REE-enriched character of the Suishoyama dike.

The specimen carries original, dated collection documentation and comes from the Eric L. Quinter Collection — Quinter's specimens are widely circulated among serious thorium/uranium mineral collectors and carry an established reputation for accurate, well-researched locality data.

Approx. specimen size: 45mm x 20mm x 5mm

Approx. specimen weight: 7.80g

Approx specimen activity on an SE International Ranger EXP: 4000 CPM

Species: Thorite, var. Thorogummite, on Ferrian Annite
Locality: Suishoyama pegmatite, Iizaka Village, Kawamata, Date District, Fukushima Prefecture, Japan
Provenance: Ex. Eric L. Quinter Collection (No. 1112, U/Th 1084)
Radioactivity: Present — handle and store per standard radioactive mineral practice