BEAUTIFUL PIECE OF DOUBLE-TERMINATED AMETHYST QUARTZ FROM LA UNION, MURCIA. DOUBLE-TERMINATED EXAMPLE WITH TWIN IN THE CENTRAL PART. PECULIAR FOR THE SHADE AND COLOR OF THE AMETHYST AND THE CRYSTALLINE FORMATION. PIECE FOR COLLECTORS.
Quartz is the most common mineral, the most abundant that can be found on earth.
It is composed of silicon and oxygen with SiO₂ formula.
According to the Nickel-Strunz classification, quartz belongs to the class of oxides, while in the Dana classification, it is considered a tectosilicate.
There are multiple varieties of quartz , colors and types.
