Overlaid tourmaline crystals demonstrating the Usambara effect.

Overlaid tourmaline crystals demonstrating the Usambara effect.
Photo courtesy of Asbjørn Halvorsen
Phenomenal Gems and Minerals

phe·nom·e·nal: known or derived through the senses rather than through the mind. 1576, "fact, occurrence," from L.L. phænomenon, from Gk. phainomenon "that which appears or is seen," noun use of neut. prp. of phainesthai "to appear," passive of phainein (phantasm). Meaning "extraordinary occurrence" first recorded 1771.

Home || The Phenomenal || The Extraordinary || Gemology || About

Judge kindly - this web is a work in progress and I am so very busy out exploring...