There is no specific measure of the average hardness of Brazils Black Lightning Quartzite as it can vary depending on the mineral composition and specific quarry from which it is sourced. However, quartzite, in general, is known for its hardness and durability. On the Mohs scale of mineral hardness, which ranks minerals from 1 (softest) to 10 (hardest), quartzite typically falls between a 7 and 8, making it harder than many other natural stones commonly used in construction and countertops.