Multi Spinel 1.5x2mm Faceted Rondelle AA Grade - 15-16 Inch missing and the ability to adapt

and the ability to adapt to change ("go with the flow")

the other being Diamond

The two most popular classes of Australian Opal are Black Opal mined in Lightning Ridge and Fire Opal

meaning that their facets were cut using industrial grade diamond

originally from the Lapis-Lazuli mine in Afghanistan

Multi Spinel 1.5x2mm Faceted Rondelle AA Grade - 15-16 Inch missing and the ability to adaptSpinel is a hard vitreous magnesium aluminum oxide, and comes in a range of other colors, but those varieties are transparent. Black Spinel not only has the dark color, but it is opaque as well, rendering its black especially deep and mysterious. Sometimes called the "Black Prince's Ruby" for its role in the English crown. It has been mistaken for ruby and sapphire at times, but can be distinguished by its structure and its lower relative hardness.