Terlingua-type Calcite from an Unusual Location

Contributed by: Chris Clemens
minID: Q8W-KQN
Date: May 2nd, 2026
Locality: Ohio, USA (See on Mindat)
Size: 7.8 x 4.6 x 10.8 cm
Weight: 390 g

Description:
Collectors of fluorescent minerals are familiar with the beautiful multi-wavelength fluorescent response of Terlingua calcite. By definition, Terlingua calcite shows a bright blue, fluorescent response under shortwave UV with bright and long-lasting phosphorescence. Under longwave UV it responds with bright pink fluorescence. Terlingua calcite is found in only one place- Terlingua, Texas. Terlingua-type calcite from other locations shows a similar fluorescent/phosphorescent response under UV, and is commonly found in several locations in Mexico, such as Boquillas Del Carmen and Nuevo Leon. However, Terlingua-type calcite has also been found in lesser-known locations, such as Indiana and Ohio in the Midwestern US.

This is a specimen of calcite collected from Southern Ohio that shows a classic Terlingua-type fluorescent response. Although the exact location for this piece is not known with certainty, it was likely collected from the Sugar Creek Stone Quarry, in Washington Court House, a location known for producing Terlingua-type calcite.

Originally posted by Chris Clemens on Nature's Rainbows in 2018.