This page gathers stones in our collection graded O for clarity — opaque. In coloured stone grading, clarity describes how freely light passes through a gem rather than simply how few inclusions it contains. An opaque stone transmits little to no light through its body, so its beauty is read at the surface: in colour, in sheen, and in the optical phenomena that move across the dome as the stone is turned.
The varieties that appear here are those whose character depends on that surface behaviour. Blue Star Sapphire, Black Star Sapphire and Star Sapphire owe their asterism to fine needle-like inclusions arranged along the crystal's growth directions; the very density of that silk both reduces transparency and creates the star. Blue Moonstone shows adularescence, the soft billowing light caused by layered feldspar structure, while Ethiopian Opal displays play-of-colour arising from the diffraction of light within its silica microstructure.
When choosing between them, weigh the strength and centring of the phenomenon, the evenness of body colour, and the quality of the polish and dome — these matter far more here than the absence of visible inclusions.
