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 ...

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.

SPORTING LISBON have finally appointed Ruben Amorim’s successor. The Portuguese giants have announced Joao Pereira, 40, as ...