Agate is a member of the Chalcedony species. It's distinctive concentric, banded,
shell-like appearance is sometimes enhanced by dying the stone as you see in the Agate slices shown above.
The bands within this stone are usually multicolored, consisting of fine quartz fibers. Some deposits have a
variety of strong to soft color variations like those that had been found in Germany, while others, like the
Brazilian Agate above, have naturally dull gray bands for which dying will create a more dramatic effect.
Since the dye will be absorbed with different intensity, depending on the composition of the bands, it is
very difficult to tell the difference between it and naturally colored agate, unless the color used rarely
appears normally in nature.
Agate is found as a ball or oblong nodule that can range in size from a fraction of an inch to several yards in
circumference. Initial important deposit finds in Germany have been pretty much worked out, but reserves remain in
Brazil and northern Uruguay. Other deposits also exist in Australia, China, India, Mexico, Madagascar, Namibia and
the states of Wyoming and Montana in the United States.
Depending upon the structure of it's band layers, color, design
or structure, Agate is commonly named in the following ways
Brecciated Agate: Broken agate nodules, naturally cemented
together with quartz.
Dendritic Agate: Whiteish or colorless, translucent chalcedony
Eye Agate: These pieces have ring-shaped designs that point to
the center, simulating the look of an eye.
Fire Agate: Has bands within itself that hold a translucent quality revealing splashes of color,
predominantly shades of red, orange, gold and yellow.
Layer Agate: Bands in these specimens are about the same size
and parallel to the outer wall of the nodule.
Moss Agate: Made of translucent chalcedony with moss-like formations
of chlorite or hornblende.
Blue Lace Agate: Named for it's subtle blue color with delicate bands
Rain Forest Agate: Just looking at this beautiful Agate stone
makes you think of the lush greens of a rain forest.
Color: Banded with all colors
Mohs' Hardness Scale: 6 1/2 - 7
Density: 2.60 - 2.64
Transparency: Opaque to Translucent