Brookite

specimen number:
2102330

location:
Magnet Cove, Hot Spring Co., Arkansas, USA

description:
A large blocky lustrous crystal of brookite 1.7 cm across embedded up on a crystallized quartz matrix. This is in good condition, the crystal is quite large for the species for this area.

The Magnet Cove complex, situated within Hot Spring County, Arkansas, United States, is a globally celebrated mineral locality and a world-class geologic anomaly renowned for producing exceptional, highly lustrous, and sharply formed black to reddish-brown crystals of brookite, a rare polymorph of titanium dioxide. Geologically, this tiny, five-square-mile district features a highly unusual, ring-shaped alkaline igneous intrusion of Cretaceous age, roughly 100 million years old, comprising exotic rocks like ijolite, syenite, and carbonatite that breached surrounding Paleozoic sedimentary strata. Intense contact metamorphism and hydrothermal alteration of the surrounding novaculite and sandstone bedrock concentrated titanium-rich fluids, allowing magnificent, tabular brookite crystals to grow inside open rock fractures and clay-filled pocket zones alongside rutile and anatase. Historically, the area was first recognized for its mineralogical diversity in the early nineteenth century, with localized open-cast quarrying and surface digging accelerating after the American Civil War to supply scientific institutions and mineral collectors worldwide. While small-scale industrial operations occurred sporadically for titanium ore, vanadium, and aggregate stone through the twentieth century, the primary activity at the core brookite localities has always been specialized specimen mining and surface trenching by private landowners and mineral clubs. Through 2026, the historic brookite diggings remain closed to general public collecting under strict private property boundaries, and classic Magnet Cove brookite specimens recovered during its late nineteenth and mid-twentieth-century peak operational eras are preserved as elite, universally recognized benchmarks of North American mineralogy.

Questions about this specimen?
Send an email or call us: 314-341-1811.