Red Fluorescent Spinel, Yenbai Province, Vietnam

Contributed by: Chris Clemens
Date: Apr 23rd, 2026
Locality: An Phú, L?c Yên District, Yên Bái Province, Vietnam (See on Mindat)
Size: 32 x 24 x 36 mm
Weight: 25 g

Description:
This specimen consists of raspberry red, octahedral spinel crystals in a white marble matrix, from the An Phu Marble Mine, Luc Yen, Yenbai Province, Vietnam. Under longwave UV, the spinel fluoresces deep, rich, red, and the marble matrix shows a moderate blue/white response. Not all red spinel is created equal in terms of fluorescence. Some fluoresces dimly, or not at all. This is a particularly bright fluorescing specimen.

Originally posted by Chris Clemens on Nature's Rainbows in 2016.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Spinel (Mindat) (RRUFF)

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