Petrified Wood – Xinjiang, China

Contributed by: Michael Crawford
Date: Apr 18th, 2026
Locality: Xinjiang, China (See on Mindat)
Size: 14 x 23.5 cm

Description:
This is a slice of petrified wood from Xinjiang Province, China. It is a Jurassic age conifer. The wood has been replaced by chalcedony. The chalcedony fluoresces yellow-brown and green under longwave UV illumination. The yellow-brown fluorescence is likely activated by organics, and the green fluorescence is activated by trace amount of uranyl ions. Under shortwave light, the chalcedony fluoresces green.

Fluorescence under longwave UV light.

Fluorescence under shortwave UV light.

Normal light.

Summary of luminescence responses:

Chalcedony (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Green
• Fluorescence under Longwave (365nm LED) UV light: Yellow
• Fluorescence under Shortwave (255nm LED) UV light: Green

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green