Neptunite, , Joaquinite-(Ce), Crossite, Natrolite

This attractive association specimen comes from the famous California State Gem Mine and features a classic assemblage of neptunite, joaquinite-(Ce), natrolite, and crossite (and some broken benitoite). The specimen is anchored by a bed of sharp, lustrous, prismatic dark reddish-black neptunite crystals, some measuring up to approximately 9 mm. Many of the neptunite crystals show damage from being formed in a tight crevasse, though several well-preserved crystals remain and display the species’ characteristic jet-black lustre.

Scattered across the specimen are numerous microscopic but well-formed crystals of rare Joaquinite-(Ce), exhibiting rich golden-bronze to orange-brown hues. These sit atop a thin layer of bright white natrolite on the blue-grey crossite matrix beneath. While individual joaquinite crystals are very small (generally under 1 mm), they are sharply crystallized and highly attractive under magnification.

Sourced from the now-closed California State Gem Mine, the type locality for Joaquinite-(Ce) and the world’s premier source of Neptunite, this specimen represents one of the most celebrated mineral localities in the world. Material from this mine is renowned for its exceptional aesthetics and mineral diversity, particularly its iconic benitoite and neptunite specimens. This example comes from the collection of Peter Tarassoff and is a fine representative of this legendary locality and its distinctive titanium-bearing mineral assemblages.