Dumortierite, Vaca Morta Quarry, Bahia, Brazil

Contributed by: Chris Clemens
minID: 27E-AWL
Date: Apr 21st, 2026
Locality: Vaca Morta quarry, Serra da Vereda, Boquira, Bahia, Brazil (See on Mindat)
Size: 9 x 5 x 10 cm
Weight: 475 g

Description:
Dumortierite is an aluminum iron borosilicate mineral that doesn\'t get much attention in the world of fluorescence, but is a lovely fluorescent species, nonetheless. This fist-sized specimen features a thick layer of blue dumortierite on a matrix of white milky quartz, from the Vaca Morta (yes, dead cow) quarry in Serra da Vereda, Boquira, Bahia, Brazil.

Originally posted by Chris Clemens on Nature's Rainbows in 2019.

Fluorescence under shortwave UV light.

Normal light.

Summary of luminescence responses:

Dumortierite (Mindat) (RRUFF)

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Blue