Tuesday, August 6, 2013
August's Birthstone, Peridot
Peridot is one of the few gemstones that occur in only one color, an olive green. It is an Iron Magnesium Silicate, and the intensity and tint of the green depends on how much iron is contained in the crystal structure. The color of individual peridot gems can vary from yellow- to olive- to brownish-green, with the darker shades of olive-green being the most prized. Because it is similar in color to an emerald, peridot stones are often confused with emeralds, and some famous emeralds have turned out to be peridot.
From ancient times and in fact right up until the eighteenth century, Peridot was referred to as topazion or topaz. The reason for this is believed to be because it was discovered on the island of Topazios, which today is commonly known as St. John's Island in Egypt. Mining for this gemstone was extremely dangerous work as the island was infested with poisonous snakes, though they were later driven into the sea by a Pharaoh.
Egypt's St. John's Island historically was the major supplier of Peridot though this supply has since been exploited and sources have been depleted. Today China, Pakistan, and the United States are all vying for the title of the world's largest Peridot supplier. There are also known supplies of Peridot in Africa, Australia, Germany, Italy, Myanmar (Burma), Norway, and Sri Lanka (Ceylon).
Peridot can be a difficult stone for a gem cutter to cut due to the fact that it's rough crystals are quite easy to break. Stones that contain numerous or heavy inclusions are generally cut as cabochons. The reason for this is that this shape provides the best possible appearance and helps to disguise inclusions.
Occasionally Peridots are enhanced with colorless oils or resins which reduce the visibility of the inclusions and improve the clarity of the stone. It is also known to occasionally improve the color.
Peridot is rated at a 6.5 to 7 on Moh's Scale of Hardness and while it is generally considered suitable for every day wear, care should be taken when wearing it in situations that could cause chipping or scratching.
Peridots can be cleaned in warm water with a mild detergent and a soft brush, then rinsed with warm water and patted dry. Always avoid ultrasonic cleaners and household chemicals that can effect the color and damage the stone. Peridots should be kept away from excessive amounts of heat and should also be kept away from long contact with perspiration, which can damage the stone over time. It is recommended that your Peridot be kept alone or separated from other jewelry items so as to avoid the gem being scratched.