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.
The best-known precious metals are gold and silver. While both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded.strophysicists use the term metal to collectively describe all elements other than hydrogen and helium. Thus, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium.