Calcite Crystals in a Septarian Nodule from Grayson County, Texas

Contributed by: Bart Pickard
Date: Mar 21st, 2026
Locality: Grayson County, Texas, USA (See on Mindat)

Description:
Lovely bright pale yellow fluorescent calcite crystals in a septarian nodule found in Grayson County, Texas.

Originally posted by Bart Pickard on Nature's Rainbows in 2016.

Fluorescence under longwave UV light.

Normal light.

Fluorescence under longwave UV light. Closeup

Normal light. Closeup

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Yellow