Quartz group from Brazil
Size-
11cm x 6.9cm x 6.2cm
Weight-
374g
You will receive the item in the photo
Quartz is a ubiquitous rock forming mineral composed of silicon dioxide.
Quartz is classified as an oxide mineral, but is structurally classified as an tectosilicate. In this structure every silica tetrahedron shares all of its oxygen atoms with neighbouring tetrahedra to form a robust three dimensional framework.
Quartz crystallizes in the trigonal crystal system.
Its hardness is 7 on the MOHs scale.
Quartz is one of the most abundant minerals on earth. Because it is chemically and physically highly stable, it forms in all theee major rock types.
Igneous- it crystallizes from silica rich magmas eg in granite and rhyolite and pegmatites.
Metamorphic- Recrystallisation under intense pressure and heat forms quartzite or quartz rich schists and geneisses.
Sedimentary- because quartz is resistant to weathering physical and chemical erosion leaves behind tough quartz grains. These grains are transported by wind and water to form sandstones beaches and riverbeds.
Minute trace elements such as iron,titanium or aluminium or natural radiation gives quartz a vast array of colours and varieties. These include clear rock crystal,pink amethyst, yellow citrine, brown smoky Quartz and pink rose quartz.