Complex Twinned Calcite, Sambava, Madagascar
Contributed by: Chris Clemens
minID: XXN-5LM
Date: Apr 16th, 2026
Locality: Basalt Quarry, Ambariomiambana, Ambohimalaza Commune, Sambava District, Sava, Madagascar (See on Mindat)
Size: 42 x 31 x 47 mm
Weight: 38 g
Description:
During 2004-2005, a limited find of morphologically complex, multiply twinned, light yellow, gemmy calcite was made in the cavities of a Basalt Quarry in Ambariomiambana, Ambohimalaza Commune, in the Sambava area of Sava, Madagascar. Of interest to fluorescent mineral collectors, these Sambava calcites often show a soft yellow to cream-colored fluorescent response activated by organic inclusions. This specimen provides a good example of fluorescent Sambava calcite. Note the complex shape of the calcite crystal.
Originally posted by Chris Clemens on Nature's Rainbows in 2022.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Yellow
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Yellow