Gems Testing Lab

    Gems Testing Lab

Menu

Agate (/ˈæɡ.ət/) is a common rock formation, consisting of chalcedony and quartz as its primary components, with a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks. The ornamental use of agate dates back to Ancient Greece in assorted jewelry and in the seal stones of Greek warriors. Use of beads necklaces with pierced and polished agate goes further back to the 3rd millennium BCE in the Indus Valley civilisation.

Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of years owing to its unique hue. Like most other opaque gems, turquoise has been devalued by the introduction of treatments, imitations and synthetics into the market. The robin’s egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur in Iran has been used as a guiding reference for evaluating turquoise quality.

Moonstone is a sodium potassium aluminium silicate ((Na,K)AlSi3O8) of the feldspar group that displays a pearly and opalescent schiller.An alternative name is hecatolite.

X