Rutile

Unknown Owner

A rather large and heavy example of an alluvial mass of rutile. There is a lot of titanium here.Minas Gerais, Brazil, is a premier geological province located within the Sao Francisco Craton, renowned for its extensive diamond-bearing and heavy mineral deposits. Geologically, the region features vast drainage systems that have eroded mineral-rich metamorphic rocks and pegmatites over millions of years, concentrating durable minerals into secondary alluvial and eluvial deposits within river gravels and terrace sands. Alluvial rutile is a significant component of these heavy mineral concentrates, typically occurring as water-worn, rounded grains or prismatic crystals in colors ranging from deep reddish-brown to black, valued both for its titanium content and as a gemstone when found in larger, transparent forms. Historically, mining and quarrying for alluvial minerals in Minas Gerais began in the early 1700s with the discovery of gold and diamonds, which spurred a massive influx of colonial exploration. While large-scale industrial dredging for rutile and ilmenite gained importance during the mid-20th century to support global pigment and metal industries, artisanal recovery of these minerals has remained a constant activity through 2026.