Agate is a term applied not to a distinct mineral species, but to an aggregate of various
forms of silica, chiefly chalcedony. Often agate coexists with layers or masses of opal,
jasper or crystalline quartz due to ambient variations during the formation process. Coral,
petrified wood and other organic remains or porous rocks can also become agatized. Agatized
coral is often referred to as Petoskey Agate or stone. Major varieties:
| Arizona Striped Agate: |
this stone is a striped agate from the southwestern USA. |
| Banded Agate: |
the bands in this stone are generally simple and clean. Gray, white and shades
of red are common naturally-occurring colors. Green, yellow and black also occur
naturally, or can be enhanced by a variety of treatments. |
| Blood Agate (Red Agate, Pigeon Blood Agate): |
this variety of agate displays a combination of milky white and a blood red with
yellow or black inclusions. |
| Blue Agate: |
agate of blue, often bright color. Often is used dyed. |
| Blue Lace Agate: |
agate with medium blue, light blue and white, finely bands in a lacy or wavy
pattern is known by this name. It is said to lighten situations and nurture
maternal impulses. |
| Botswana Agate: |
this agate hails from the African country Botswana. It has a gray background,
banded with fine, parallel lines of brown, light gray, tan, mahogany, pink and
white, this gemstone may be almost mined out. |
| Brazilian Agate: |
brazilian agate occurs in brownish tones interlayered with white and gray. It is
often dyed in various colors for ornamental purposes. |
| Butterscotch Agate (Yellow Jade): |
agate of butterscotch yellow color; looks like yellow jade. |
| Condor Agate: |
this stone comes from a difficult-to-reach 7,000-foot elevated plateau in
Patagonia, Argentina, discovered in 1992. The agate's bright reds and yellows
are made even more vivid by their contrasting bands of cooler, more-subtle hues. |
| Crazy Lace Agate (Fashion Jasper): |
this agate is composed of twisting and turning ("crazy") bands of various bright
colors, it has a complex banded pattern. |
| Dendritic Agate: |
dendritic agate has beautiful fern like patterns on it. |
| Dryhead Agate: |
this bright and well patterned agate from Montana features wild fortification
banding in vivid hues of reddish-orange. |
| Fairburn Agate: |
fairburn agate from South Dakota is characterized by sharp "holly leaf" banding,
somewhat resembling an aerial view of an old fort, hence the name fortification
agate. The difference from most other agates is the very large range of colors. |
| Fossil Agate: |
this agate formed naturally as a replacement of organic material. |
| Golden Agate: |
this mottled stone contains yellowish hues that include reddish, honey, brown and
specks of black and white. Interestingly, an amber-colored type of heat-sensitive
glass invented in the late 1800s was also named golden agate. |
| Greek Agate: |
greek agate is a name given to pale white to tan colored agate. |
| Icy Agate: |
this variety of agate is a beautiful combination of blue and white. |
| Mexican Agate: |
mexican agate, showing only a single eye, has received the name of "cyclops agate". |
| Montana Agate: |
with its warm, deep browns and oranges, Montana agate is found around the
Yellowstone River and its tributaries. Gravel deposits from the Pleistocene Age are
the main source. |
| Moss Agate (Mocha Stone): |
this agate is clear with mottled, leaf-like inclusions, it has an organic appearance. |
| Natural Agate (Multicolor Carnelian): |
this agate variety incorporates shades of butterscotch, orange, yellow and cream. |
| Ocean Wave Agate: |
this is a recently discovered rock from Madagascar. It was found about 400 yards from
a major ocean jasper deposit. Ocean wave agate has gentle wavy patterns with a wide
variety of colors: green, blue, black, red, pink, white, lavender, orange and gold. |
| Red Agate: |
agate of butterscotch, orange, yellow and cream color. Can be dyed or heat treated. |
| Tree Agate: |
this gemstone is white or off-white agate dappled with green flecks. |
| Turritella Agate: |
turritella agate is formed from fossil Turritella shells silicified in a chalcedony
base. Turritella are spiral marine gastropods having elongated, spiral shells composed
of many whorls. |
Other forms of agate include Carnelian Agate (usually exhibiting reddish hues), Ellensburg
Blue Agate, Tube Agate (with visible flow channels), Queensland Agate, Fire Agate (which
seems to glow internally like an opal), Plume Agate, Fortification Agate (which exhibit
little or no layered structure), Rainbow Agate, and so on.