My stones. Part VI
12:18:00Agate is a microcrystalline variety of quartz (silica), chiefly chalcedony, characterised by its fineness of grain and brightness of colour.
The stone was given its name by Theophrastus, a Greek philosopher and naturalist, who discovered the stone along the shore line of the river Achates sometime between the 4th and 3rd centuries BC. Colorful agates and other chalcedonies were obtained over 3,000 years ago from the Achates River, now called Dirillo, in Sicily.
Agate is one of the most common materials used in the art of hardstone carving, and has been recovered at a number of ancient sites, indicating its widespread use in the ancient world. It has a lot of different varieties.
A Mexican agate, showing only a single eye, has received the name of cyclops agate.Included matter of a green, golden, red, black or other color or combinations embedded in the chalcedony and disposed in filaments and other forms suggestive of vegetable growth, gives rise to dendritic or moss agate. Dendritic agates have fern like patterns in them formed due to the presence of manganese and iron oxides. Other types of included matter deposited during agate-building include sagenitic growths (radial mineral crystals) and chunks of entrapped detritus (such as sand, ash, or mud). Occasionally agate fills a void left by decomposed vegetative material such as a tree limb or root and is called limb cast agate due to its appearance.
Greek agate is a name given to pale white to tan colored agate found in Sicily back to 400 B.C. The Greeks used it for making jewelry and beads. Today any agate of this color from Sicily, once an ancient Greek colony, is called Greek agate. Yet the stone had been around centuries before that and was known to both the Sumerians and the Egyptians, who used the gem for decoration and religious ceremony.
Another type of agate is Brazilian agate, which is found as sizable geodes of layered nodules. These occur in brownish tones interlayered with white and gray. Quartz forms within these nodules, creating a striking specimen when cut opposite the layered growth axis. It is often dyed in various colors for ornamental purposes.
Other forms of agate include Lake Superior agate, carnelian agate (usually exhibiting reddish hues), Botswana agate, Ellensburg blue agate, blue lace agate, plume agates, tube agate (with visible flow channels), fortification agate (which exhibit little or no layered structure), fire agate (which seems to glow internally like an opal) and Mexican crazy-lace agate (which exhibits an often brightly colored, complex banded pattern) also called Rodeo Agate and Rosetta Stone depending on who owned the mine at the time.
Agate was highly valued as a talisman or amulet in ancient times. It was said to quench thirst and protect against fever. Persian magicians used agate to divert storms. A famous collection of two to four thousand agate bowls which was accumulated by Mithridates, king of Pontus, shows the enthusiasm with which agate was regarded.
All the pictures are of the stones and jewellery I own and taken by me.
If you fancy a piece of soutache jewellery with any of the stones on my website -- send me a message or convo me on etsy.
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