Heliodor and Aquamarine with Surface Etching

Heliodor and Aquamarine with Surface Etching

Aquamarine and heliodor crystals from China with distinctive etch pits
Figure 1. Aquamarine (left) and heliodor (right) crystals from China, showing distinctive etch pits.

During an ongoing beryl characterization project, aquamarine and heliodor beryl samples from the GIA Museum collection revealed distinctive etch features on each of their crystal faces. These two samples were reported by the donor as being from China.

Heliodor crystal with compressed hexagonal etch features
Figure 2. Heliodor viewed with differential interference contrast filters, showing compressed hexagonal etch features.
Aquamarine crystal with hexagonal and uneven etch features
Figure 3. Aquamarine viewed with differential interference contrast filters, showing hexagonal and uneven etch features.

The etch pits seen on these samples are markedly different from those of Ukrainian heliodor (Etch pits in heliodor and green beryl from the Volyn pegmatites, Fall 2023 G&G). While Ukrainian heliodor exhibits rectangular etching, these specimens have rounded six-sided shapes akin to compressed hexagons adorning their prismatic faces. These features are more prominent on aquamarine than heliodor.

About the Authors

Rhiana Elizabeth Henry is a postdoc research associate, and Adriana Robinson is a digital imaging technician, at GIA in Carlsbad, California.

Back to blog