- Chalcedony (also spelled Calcedony), is a catch all term that includes many well known varieties of cryptocrystalline Quartz gemstones. The two main varieties are Chalcedony, which is uniformly coloured, and Agate, characterized by bands/zones of different colours.
- Agate is distinguished by its multiple colours that are often vivid. The bands of colour may be white, red, blue, grey, brown, or black. These are irregular and sometimes curved, caused by traces of iron and manganese. The parallel bands follow the wavy contour of the cavity where silica gel solidified.
- Agate's name was derived from the site of its initial discovery, the River Achates (now Dirillo), in Southwest Sicily.
Legends & Lore
- Said by the ancients to render the wearer invisible, Agate has been admired by humanity for thousands of years. Its beauty and durability have prompted man to use it in both practical and ornamental forms. Valued by the Ancient Sumerians and Egyptians who used it for amulets, receptacles, and ornamental pieces, Agate is one of the oldest known gems.
- The Greeks and Romans carved it into cameos (i.e. a gem carved in relief) and intaglios (i.e. a gem carved in negative relief). In Roman times Agate intaglio signet rings were particularly popular.
- Agate is mentioned in the bible as being one of the "Stones of Fire" (Ezekiel 28:13-16) given to Moses that featured in the breastplate of his brother and high priest Aaron (Exodus 28:15-30) and a variety of Agate, Sardonyx is one of the twelve gemstones set in the foundations of the city walls of Jerusalem (Revelations 21:19). As compiled by Andreas, Bishop of Caesurae, one of the earliest writers to tie the Apostles with the symbolism of the twelve gems of Jerusalem, the Apostle for Sardonyx is James.
- Agate was especially valued during medieval times where one of the more outlandish uses is binding an Agate to each horn of your oxen to ensure a good harvest. The danger here is that your appropriately Agated beasts of burden may then become invisible and a little hard to find!
- In 1709 a Brazilian priest planned to use Agates as antigravity devices on an air ship he had designed.
- Agate is believed to cure insomnia, ensure pleasant dreams, protect from danger, promote strength, healing and a bold heart. Wearers are believed to become temperate, continent and cautious. In antiquity Agate was regarded as cooling gem capable of reducing fever, quenching thirst, quieting the pulse and ensuring good health and a long and prosperous life.
Just The Facts
- Agate is formed in a unique way and many fossils are actually Agatized material that has replaced the original organic substance. For example, petrified wood is fossilized wood that has had its organic matter replaced by Agate.
- The main conditions necessary for Agate formation are the presence of silica from devitrified volcanic ash, water from rainfall or ground sources, manganese, iron and other mineral oxides that form the bands and inclusions.
- Agate comes in many different forms ranging from transparent to opaque. Varieties include Blue Agate, Blue Lace Agate, Crazy Lace Agate, Green Agate, Indian Agate, Moss Agate, Fire Agate, Tree Agate, Onyx, Sardonyx and Wood Agate.
- The most popular varieties are: Blue Lace Agate, which has white bands swirling on a blue background; Moss Agate, so named for its moss-like pattern; and Fire Agate, a brown-bodied gem containing yellow, green, and orange spots, with an iridescent shimmer like Opal.
- As there are so many varieties of Agate, it is largely up to the buyer to determine its value. Most Agate is in the low price range but some picture stones, carvings and unique pieces may command higher prices. The popularity of Fire Agate has increased in recent years, as has its price mainly because its colour only appears when cutters polish through the inner layers of silica, thereby creating iridescence. If they polish too much and one too many layers are removed, the gem will be ruined!
- Agate is mined in U.S.A, Mexico (Fire Agate), Australia, Brazil, Canada, South Africa, Uruguay, India and many other countries.
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8 July 2007
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