Catherine Bell (I) Catherine was born in London, but moved to California with her Iranian mother at age 2. Her mother still acts as her personal assistant. As a child, she acted in various TV adverts. She went to UCLA to study biology, but dropped out to become a model in Japan.
When gemstones are identified by category, the following categories may apply: 1  Diamonds â considered the most precious stone in the world. 2  Corundum â contains gemstones like sapphires and rubies. 3  Chrysoberyl â alexandrite and catâs eyes are two common stones of this type.here are other ways to evaluate types of gemstones. People may classify them by hardness on the Mohs scale, by color, by rarity, or by popularity. What is really most important in considering different types is how they appeal and how well they will hold up when used in certain ways.
Beside black, red (rubellites) and yellow, tourmalines also occur as green stones. The green gemstones come the species of tourmaline called elbaite, which is further divided into two varieties: verdelite and indicolite, the latter also available in blue.hough popularly known for their white variety, pearls are also available as black, yellow and green stones. Light green pearls are produced by Japanâs Akoya oysters, while the dark green gemstones come from the black pearl oyster, whose pearls are not necessarily black, but may also be shades of green and blue.