Alexandrite in Beryl var. Emerald from A Franqueira, A Cañiza, Pontevedra, Galicia, Spain

Contributed by: Daniel C. Montero
Date: May 4th, 2026
Locality: A Franqueira, A Cañiza, Pontevedra, Galicia, Spain (See on Mindat)

Description:
Alexandrite is a variety of chrysoberyl.

The most striking characteristic of this gem and that gives it more value is that it has a different color depending on whether it is given natural or artificial light: green under daylight and purple red under incandescent artificial light.

In the photo we can see its red fluorescence under longwave UV light.

Most common activator: Cr³⁺
Other activators: Mn⁴⁺, V²⁺

Originally posted by Daniel C Montero on Nature's Rainbows in 2023.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Alexandrite (Mindat) (RRUFF)

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