“The vein being mined contained antimony, gold, silver and copper and was located in a shear zone between two granite walls ... is pretty short as the cave network only has two forks, expect ...

Ruby is an incredibly durable gemstone if there are no treatment-related durability concerns. - Courtesy Jan Goodman Co. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale.

Ruby and sapphire are varieties of the mineral corundum. - Courtesy Hamilton Jewelers Ruby is one variety of the corundum mineral species, which also includes sapphire. Ruby is highly regarded and can ...