A Beginner’s Guide to Agate Identification
A Beginner’s Guide to Agate Identification
Agates are a type of variegated chalcedony, which is part of the quartz family, that are known for their beautiful markings and colors. Considered a semi-precious gemstones, agates are named for the Achetes River in Sicily, where they were first identified. Agates are volcanic rocks, formed when molten lava cools and cavities left behind by trapped gasses are filled by minerals and silica molecules deposited in layers. Given time, these minerals are compounded into concentric bands and other patterns that make agates stand out from other gemstones. Agates have long been used in industry and art due to their hardness and colors. Bright purple and pink agates make beautiful jewelry, art, and décor, as seen on 55-55 Marine Drive.
How to Tell Agates Apart from Other Stones
Agates stand out from other semi-precious gemstones due to their unusual patterns and colors. Most agates are usually banded, with stripes of color running the length of the stone. Some agates have circular patterns along with or instead of bands. These patterns are called mossy or plume inclusions and are helpful in identifying specific types of agates. Agates are sometimes confused with jasper, which are also multi-colored and have banding or mossy inclusions. Jasper is also a type of variegated chalcedony, which gives the types of rock a very similar look to agate. The main difference between agate and jasper is their diaphaneity, or opaqueness. Jasper is opaque, meaning its color is solid and no light is able to pass through the stone. Agates vary between semitransparent and translucent, so some degree of light is able to pass through them. It can sometimes be difficult to determine if a piece of chalcedony is opaque or not, and sometimes a specimen will have both opaque and translucent areas, therefore containing both agate and jasper. However, diaphaneity is usually the best way to determine the difference between the two.
There are many types of agates found all over the world. Some are named for their colors and patterns, while others are named for the location in which they are found, or for the formation in which they grow. Some types of agate are more rare than others, while some can be quite commonplace.
Agates World Wide
Botswana agates are named for the country in which they are found, and are classified by their banding of thin parallel lines in the colors purple, white, or peach. Lace agates display patterns that resemble lace or waves, hence the name. Like many other types of stone, agates can also form in geodes. Layers of agate surround a geode cavity lined with quartz for a stunning, raw gemstone. Other types of agate include eye agate, which is named for its perfectly round concentric rings, and fire agate, an iridescent type of agate that looks like it is on fire when lit from behind. Perhaps one of the most unique types of agate is the fortification agate. The banding of the fortification agate all connects together, creating a pattern that looks like a medieval castle, complete with walls and a moat. Snakeskin agate is so named for its pattern resembling the scales of a snake.
Some types of agate are so popular that they are often recognized as separate gemstones. Onyx, which is usually solid black or banded black and white, is one such type of agate. Sardonyx, an agate characterized by red, brown, white, or black banding is another example of this. Moss agate is a variety characterized by a pattern that resembles moss growing on a rock. It’s usually green in color, however; it is technically not a true agate as it lacks banding.
There are so many varieties of agate that one can find an agate of virtually any color, ranging from earth tone brown agates to brilliant pink, blue, or purple. Lighter shades of agate specimens can also be artificially dyed any color of the rainbow, however; agate is so spectacular on its own, that there is actually a variety of agate that when sliced thin shows the entire spectrum of a rainbow. This type is unsurprisingly called rainbow agate. Agates are a beautiful gemstone that make a great addition to any jewelry collection, gemstone collection, or room décor. Because of the variety of color, agates can match any color scheme, from subtle neutral tones, to bright vibrant palettes.