Luxullianite from Luxulyan Cornwall UK
Size-
7.8cm x 3.1cm x 2.5cm
Weight-
83g
You will receive the item in the photo
Luxullianite is a rare type of porphyritic iguana rock (specifically a tourmalinized granite) rather than a single mineral.
Because it is a multi-mineral rock, it does not have a single crystal system or mineral class of its own, its properties are determined by its component minerals (mainly orthoclase feldspar tourmaline and quartz)
It formed roughly 280 million years ago from st Austell granite complex. As the original granite crystallized,boron- and silica rich hydrothermal/pegmatitic fluids injected into cavities and cracks. This process known as tourmalinization,chemically altered the rock. It replaced parts of the original matrix with striking needle like black tourmaline clusters while leaving the large salmon pink feldspar crystals intact.
The overall hardness of the rock is 6-7 on the MOHs scale.
