Agate
- Agate is a form of
chalcedony which is a variety of
quartz.
- The most common use for agate is as an
ornamental stone. It is used for jewellery, vases, book ends,
sculptures, table tops, and tiles. It is also collected by rockhounds
because of its natural beauty.
-
Agate is composed primarily of microscopically
crystallized silica (SiO2) and often occurs as a cavity filling in
lavas.
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Chachahuen Agate, Sierra de Chachahuen
Newquen, Patagonia, Argentina |
- This slice of
white, gray & brown banded agate has been cut with a diamond blade and
polished to a shiny, glassy finish. If tapped, it sounds like glass. It
is
translucent. The bands are concentric, taking the shape of
the agate
nodule or
geode it filled in.
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SPECIMEN ORIGIN: BRAZIL |
- This
agate nodule has been cut in half and polished. Notice how the inside is
solid but looks translucent and milky.

SPECIMEN ORIGIN: BRAZIL
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SPECIMEN ORIGIN: BRAZIL
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- Natural colors are brown, black, tan and white. Since agate slices come
from geodes and nodules, the shape of the slice reflects the most common
geode shapes. The most common shapes are round and oval.

SPECIMEN ORIGIN: AUSTRALIA |

SPECIMEN ORIGIN: BRAZIL |
Crazy Lace Agate
- Crazy Lace Agate is a descriptive name that refers to the
banding that undulates and swirls
- the primary colours of the banding are brown, cream, red and
orange alternating in thin lines
- the source of most Crazy Lace agate is Mexico
- it is a favourite stone used in lapidary to make cabs
(cabochons) for pendants & earrings
- stones are opaque to tranlucent
- it has a hardness of 6.5 to 7 on the Moh's scale of hardness and
takes an excellent polish
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Blue Lace Agate
- Blue Lace Agate is known by its distinctive pale blue and white
banding
- its delicate decorative banding resembles lace
- the source of Blue Lace Agate is in Africa - South Africa &
Namibia
- it has a hardness of 6.5 to 7 on the Moh's scale of hardness and
takes an excellent polish
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Coloured Agate Slices
- This
slice of agate has been dyed to show how a natural stone can have its
color changed.
- Many agate slices are available in gift shops
with bright pink, purple & green colors. They have all been dyed because
people like the colors. The colors are not natural. They are artificial.
The agate slices are soaked in "mineral baths" and heated to give them
the brilliant artificial colors.
- Agate is
formed in layers and usually follows the shape of the cavity.
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SPECIMEN LOCATION: Royal Ontario
Museum, Ontario, CANADA |
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