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.

Rose and Bruno Mars lead the Billboard Global Excl. US this week with "Apt.," which is tied with ... [+] Miley Cyrus' "Flowers" and Harry Styles' "As It Was" as the second-longest-ruling leaders ...