Coral
For Thousands of years, cultures around the world have prized coral as a gem and credited this product of the sea with magical powers. First century Romans used it to ward off evil and impart wisdom. It’s still worn in modern-day Italy as protection against the “evil eye” and as a cure for sterility. There are two types of gem coral. One type comes in a variety of lighter shades: White, cream or pink, various shades of red or orange, and occasionally blue, purple, or light grayish violet (known as “lavender” in the trade). The other coral type is black, dark brown, or sometimes light brownish yellow (often called “golden”). All coral is composed of the remains of skeleton-like support structures that were built by colonies of the tiny marine animals. These coral polyps, as they’re called, are close relatives of the more familiar coral reef builders. Coral jewelry, in the form of beads, cabochons, and especially small carvings and cameos, has been popular in Europe since Roman times. Its popularity is strong in both North and South America. At one time, Asian countries used coral jewelry in the twentieth century. World demand for coral jewelry remains high, even though a number of factors have combined to drastically reduce the supply of new material in recent decades. These factors include pollution, over-harvesting, and increasing national and international environment protection efforts. For centuries, the most prized qualities of coral came from the Mediterranean Sea, along the coasts of Algeria, France, Italy, Morocco, Spain, and Tunisia. Unfortunately, pollution and depletion have devastated these waters. Australia as another once-important source is now prohibits the export of all native coral. The state of Hawaii protects black “King’s” coral as an endangered species. All these factors limit modern supplies of coral, but the availability of high-quality pieces guarantee it a permanent place in the antique market.
Sources
Japan
Malaysia
Philippines
Hardness & Toughness
Hardness 3 to 4 on Mohs scale
Toughness Fair to good
Stability
Environmental Factor & Reaction
Heat: Blackens or burns if exposed to flame.
Light: Generally stable but dyed material may eventually fade
Chemicals: Easily attacked by acids and other chemicals
Care & Cleaning
Warm soapy water is always safe. Ultrasonic is too risky and steam cleaning should never be a way to clean a coral.
Source: GIA's Library