agate

This antique, Victorian era brooch circa the late 1800s, features a large banded agate set at the center of a gold-filled frame with repoussé detailing
Banded agate set in a Victorian Era brooch
Variety:  Agate
Species:  Chalcedony
​​Mohs Hardness:  7.0 out of 10
Color:  Color varies.  Agate is chalcedony with curved or angular bands or layers.
RI:  1.535 to 1.539 (1.53 to 1.54 spot reading)
Birefringence:  Not detectable
SR/DR/AGG:  AGG
Spectrum:  Not diagnostic
Fluorescence:  Generally inert
SG:  2.60 (+0.10/-0.05)

agate facts

Vintage Southwestern style brooch featuring an attractive banded agate tablet set in a sterling silver, beaded feather setting
Polished agate set in a handmade silver brooch

Agate is a transparent to opaque gem known for its banded appearance.

Agate is a variety of chalcedony, which is a microcrystalline variety of quartz.

Most agate is found inside nodules in ancient volcanic lava.

Agate is found in many places, worldwide, including the United States, Africa, Asia, Brazil, Egypt, Germany, India, Italy, Mexico and Nepal.

​Agate ranges from transparent to opaque and is known for its parallel banding.

Scottish Agate Jewelry became popular in the 1850s due to Queen Victoria's infatuation with Scotland.  A large amount of Scottish Agate Jewelry was actually produced in England.

Lace Agate describes agate with lace-like patterns that can resemble swirls, bands, or zig-zags.

Agate is a September birthstone, and is a 12th and 14th anniversary gemstone.
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Agate Gallery

All photos courtesy of Scott Papper, GIA GG, AJP, CMA (NAJA)