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.
Kidney stones are of different types- uric acid crystals, calcium oxalate crystals, Cystine stones and many others. They come in different sizes and shapes too. Some are as small as a grain of sand, some as large as a marble. Some stones are smooth, others are rough and have cutting edges.