Chalcedony Properties Facts and Photos
1. What is Chalcedony?
2. Different Varieties of Chalcedony
3. A Few More Facts
4. Shop for Chalcedony
What is Chalcedony?
Chalcedony which it's generally agreed should be pronounced kal~SED~uh~nee is a fine grained cryptocrystalline variety of quartz.
It tends to have a waxy lustre, is usually translucent and can be found in white, grey, blue or brown. Stones can also exhibit many other colours due to various impurities. In agate and jasper both of which are varieties of chalcedony a combination of several colours can often be seen.
Blue chalcedony is particularly popular as a decorative stone but is often dyed.
Graded 6.5 to 7 on Mohs scale of hardness, chalcedony is a fairly hard material that can be found pretty much worldwide.
The finest material comes from India, Madagascar, Burma, Brazil, Mexico and the USA.
Different Varieties of Chalcedony
Jasper, agate, carnelian, onyx, chrysoprase and bloodstone are all varieties of chalcedony. The colour of carnelian is caused by the presence of iron oxides. These are chemical compounds of iron and oxygen.
The green colour of chrysoprase is caused by impurities of nickel. The green colour of bloodstone is believed to come from chlorite, amphibole and pyroxene. The distinctive red inclusions for which bloodstone is well known are caused by iron oxides.
Some of the lesser known varieties of chalcedony include plasma, sard and sardonyx. Sard occurs in shades of light to dark brown and sardonyx features bands of sard in addition to white chalcedony.
Stones with distinctive and colourful bands are mostly referred to as agate. When the bands are black, white, dark brown or just one colour it's known as onyx.
The main difference between agate and onyx is the bands. In onyx they're parallel whilst in agate they're curved.
A Few More Facts
Chalcedony has been used by man for thousands of years. It's believed to have been one of the earliest materials used for tools and weapons. Other varieties including agate, flint, jasper and petrified wood were also widely used.
Considered to be a sacred stone by the Native American Indians, chalcedony was used to promote stability within the tribe.
In ancient times it was used to make goblets lined with silver. These were believed to offer protection against poisoning.
At the Palace of Knossos which is the largest Bronze Age site on the Greek island of Crete, chalcedony seals have been found which date to approximately 1800 BC.
When used for its metaphysical healing properties chalcedony encourages generosity, protects against nightmares, fear of the dark, hysteria, depression and combats negative thoughts.