Ruby and sapphire are the two varieties of the mineral corundum. Their exceptional hardness is surpassed only by diamonds. Red corundum is called ruby, and all other colors are called sapphire. The cut-off between ruby and pink sapphire on one end and plum sapphire on the other has long been a subject of controversy. Of course, gem dealers want the gem they're selling to be classified as a ruby because the name alone increases its value.
The different geographical sources of ruby are known for characteristic colors and qualities, although they all produce a variety of gem material. Burma is famous for producing the greatest amount of top quality ruby-a fine, clear, deep red. Thailand is known for dark red to brownish-red stones. Typical Ceylon (Sri Lanka) rubies are medium light in tone. And Africa is known for small, sheet-like, purplish-red material.
Burma is the most important source of ruby today. Other producers are the island of Sri Lanka-(formerly Ceylon), the countries of' Thailand, Kampuchea (Cambodia), India and Australia, various localities in Africa and our own state of North Carolina.
Sapphire occurs in colors ranging from very light to dark blue to violetish-blue, bluishgreen, yellow, slightly reddish-orange, brown, nearly opaque black, colorless pink, violet and pinkish-orange. Corundum (sapphire's mineral name) occurs in red, but this is what we know as ruby. A particularly lovely pinkish-orange is referred to as "padparadscha" which is taken from the Sinhalese for "lotus-colored ' " Although sapphire is found in many colors, these are not all commercially available at any given time. Some are so rare they are collectors' items.
The color of emerald is a beautiful distinctive hue of green, colored by chromium and or vanadium. The finest emeralds have an intense medium green to slightly bluish green color. All emeralds contain inclusions, but the finest quality are very faint and not visible to the naked eye. The mines in Columbia, Muzo and Chivor produce the largest most beautiful emeralds. In the last decade, Africa has been producing many fine quality emeralds.
Emeralds have a hardness of 7.5 -8 on the Moh's scale of hardness, but they do tend to be brittle. Emeralds should not be put in ultrasonic machines or be steam cleaned. Avoid rapid temperature changes and any type of chemicals. The best way to keep your emerald jewelry clean is with warm water and a very soft toothbrush.
About
Diamonds
About
Gold
About Colored stones
