Calcite and Sulfur from the Maybee Quarry, Maybee, Michigan

Contributed by: Chris Clemens
Date: Apr 22nd, 2026
Locality: Maybee Quarry, Maybee, Exeter Township, Monroe County, Michigan, USA (See on Mindat)

Description:
A fluorescent beauty from the Midwest. Yes, there are fluorescent minerals in the Midwest! Brightly fluorescent/phosphorescent calcite rhombs on yellow sulfur crystals, from the Maybee quarry, Maybee, Monroe Co., Michigan. In the close-up view below, the calcite crystals can be seen fluorescing blue/white under long wave UV. Although the sulfur appears to be dimly fluorescent also, this is an illusion caused by the translucency of the sulfur transmitting the fluorescent light emitted by the calcite.

The calcite is brightly fluorescent under both longwave and shortwave UV and is also strongly phosphorescent. The fluorescent response is brightest under longwave UV, but the strongest phosphorescence occurs following shortwave UV.

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

Fluorescence under shortwave UV light.

Afterglow after exposure to shortwave UV light.

Fluorescence under longwave UV light.

Afterglow after exposure to longwave UV light.

Normal light.

Normal light. Closeup

Fluorescence under shortwave UV light. Closeup

Afterglow after exposure to shortwave UV light. Closeup

Fluorescence under longwave UV light. Closeup

Afterglow after exposure to longwave UV light. Closeup

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: White
• Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: White
• Fluorescence under Longwave (365nm LED) UV light: White
• Afterglow after exposure to Longwave (365nm LED) UV light: Green