Though not quartz, this mineral has a variety known as Mexican Onyx.
Though not quartz, this mineral has a variety known as Mexican Onyx. Veterite and Aragonite are polymorphs of this mineral which comes in varieties such as Satin, Dogtooth and Iceland Spars. It notably displays Rhombohedral cleavage and its unique optical properties cause birefringence. This mineral which is responsible for the formation of most caves is the primary component of the skeletons of Coral. This mineral is also noted for reacting violently to acids just like the rocks formed from it such as limestone and marble. FTP, Name this Carbonate mineral, Number 3 on the Mohs Hardness scale with Chemical Formula CaCO3.
Though not quartz, this mineral has a variety known as Mexican Onyx.
Calcite