IOLITE IN ESTATE JEWELRY AND VINTAGE JEWELRY
Iolite is sometimes called "water sapphire" as it resembles a sapphire from the top, yet looks clear or "watery" from the sides. This effect results from the gemstones strong trichroism of iolite. In one direction the crystal appears dark blue or violet, in the opposite direction the stone is colorless, gray, yellowish and in a third direction it may appear light blue or violet.
BIRTHDAYS AND ANNIVERSARIES
Iolite is the gemstone suggested for the 21st wedding anniversary celebration.
ORIGIN OF NAME
The name iolite was derived from the Greek word "ios" which means violet. Mineralogists call the stone cordierite, a name given to honor the French geologist, Pierre Cordier.
HISTORY
Prior to the 1980s, iolite was primarily considered a collector's stone as little was produced or sold. It is often sold mistakenly to replace tanzanite or sapphires because of the similar blue-violet color.
LEGENDS
Iolite was once thought to be the "Viking's compass." Vikings would use the thin colorless slices of iolite on cloudy days to locate the position of the sun. The stone would cancel the impact of the haze and mist and work to polarize light.
AREAS FOUND
Most iolite comes from India, Sri Lanka, Tanzania and Brazil. Iolite also comes from Myanmar, Madagascar, Zimbabwe and Namibia.
ESTATE JEWELRY AND VINTAGE JEWELRY CARE INSTRUCTIONS
Iolite is not usually a treated stone. Ultrasonic use is considered risky for estate jewelry and vintage jewelry pieces. Acids and sudden temperature changes should be avoided.
EVALUATION
Iolite is valued higher when it's blue-violet color resembles tanzanite or sapphires. Iolite looses value when the color is dark and the flaws are visible.
TECHNICAL DATA
Crystal system:orthorhombic
Cleavage: distinct in one direction
Refractive Index1.53 - 1.58
Optic: double refracting and biaxial negative
Specific Gravity: 2.56 - 2.66
HARDNESS
With a hardness of 7 to 7.5, on the Mohs' Scale, iolite's toughness is rated fair.
SPECIFIC GRAVITY
The specific gravity is the ration of the density of an object when compared to water. In the simplest testing, it is simply the weight of a mineral compared to its volume. The volume of the stone is measured by the amount of water in displaces.
