Thomsonite is actually internal reflections from copper inclusions (additional minerals trapped within the gemstone). U.P. Thomsonite is formed in a similar process as agates, trapped air pockets within volcanic basalt fill with prehnite (mineral base of U.P. Thomsonite) and microscopic bits of copper.

What is Thomsonite stone?

Thomsonite is the name of a series of tecto-silicate minerals of the zeolite group. ... The crystal system of thomsonite is orthorhombic. The Mohs hardness is 5 to 5.5. It is transparent to translucent and has a density of 2.3 to 2.4. It may be colorless, white, beige, or somewhat green, yellow, or red.

Is Thomsonite worth money?

The typical value range of these thomsonites is anywhere from $5 to $20 per gram, according to Keith. The three main factors that account for the price of this gem are linear fractures, “eyes”, and greenish hues.