search
  • Sign In
    Sign Up
  • English speaking customer support only

    Toll Free - USA & Canada only:
    1-800-464-1640

    International:
    +66-39303404

  • Change Language
  • USD

Agate Gemstones

Banded Agate from India
Banded Agate from India

Quartz is one of the most common minerals on earth and the quartz family is made up of two separate branches. When most people think of quartz, they think of what is known as macrocrystalline quartz, which includes rock crystal, amethyst, citrine, smoky quartz and rose quartz. Macrocrystalline quartz, as the name suggests, has large crystals which can be distinguished by the naked eye. This type of quartz is mainly transparent to translucent, with a vitreous luster.

The other type of quartz is known as cryptocrystalline quartz. It has microscopically (or submicroscopically) small crystals and is usually translucent to opaque, with a waxy to greasy or dull luster. This kind of quartz has fibrous and granular subcategories. The fibrous varieties are known under the name chalcedony, but this name covers a remarkable variety of stones.

Dendritic Agate from India
Dendritic Agate from India

In practice, the name chalcedony refers to solid colored cryptocrystalline quartz, especially of a light color. The patterned varieties tend to have their own names. The most famous of these include agate, which is distinguished by its bands of color; black and white layered material known as onyx (this is usually dyed to produce a uniform black); carnelian, which is yellow-orange to reddish-orange and is colored by iron; and chrysocolla, a rare type of vivid blue-green cryptocrystalline quartz that is colored by copper.

The patterns of agate are so distinctive that a number of different varieties are commonly identified in the trade. They include eye agate, which forms ring shapes with a point in the center; dendritic agate, which is distinguished by its moss-like patterns; and fire agate, a type of agate that has an unusual iridescence.

Agate was used as a gemstone by the Egyptians at least 3,000 years ago. In modern times, agate has a special association with the Idar-Oberstein region in Germany. Idar-Oberstein was an important source of agate until the 19th century. The region was favored with good local sandstone for producing cutting and polishing wheels, and water power to work the wheels.

Fire Agate from Mexico
Fire Agate from Mexico

Fortunately for Idar-Oberstein, large deposits of agate were discovered in Brazil in the 1830s, just as the agate mines in Germany were starting to be worked out. The agate polishing industry in Germany flourished as a result and produced high quality objets d'art, beads, rings, pendants, brooches and cameos.

Today agate continues to be mined in Brazil. It is also mined in Uruguay, India, Australia, China, Madagascar, Mexico, Mongolia and Namibia.

  • First Published: January-27-2009
  • Last Updated: January-22-2019
  • © 2005-2019 GemSelect.com all rights reserved.
    Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited.
Pinterest Board Names
More Shapes
Popular Gemstones
  • Sapphire
  • Emerald
  • Ruby
  • Aquamarine
  • Zircon
  • Opal
  • Topaz
  • Tourmaline
  • Garnet
  • Amethyst
  • Citrine
  • Tanzanite
All Gemstones (143)
A B C D E F G H I J K L M N O P Q R S T V Z
  • Actinolite Cat's Eye
  • Agate
  • Agate Geode
  • Almandine Garnet
  • Amazonite
  • Amethyst
  • Amethyst Geode
  • Ametrine
  • Ammolite
  • Andalusite
  • Andesine Labradorite
  • Apatite
  • Aquamarine
  • Aventurine
  • Beryl
  • Black Opal
  • Bloodstone
  • Boulder Opal
  • Calcite
  • Carnelian
  • Cat's Eye Apatite
  • Cat's Eye Aquamarine
  • Cat's Eye Augite
  • Cat's Eye Gemstones
  • Cat's Eye Moonstone
  • Cat's Eye Opal
  • Cat's Eye Scapolite
  • Chalcedony
  • Charoite
  • Chocolate Opal
  • Chrome Diopside
  • Chrome Tourmaline
  • Chrysoberyl
  • Chrysocolla
  • Chrysoprase
  • Citrine
  • Color-Change Diaspore
  • Color-Change Fluorite
  • Color-Change Garnet
  • Color-Change Sapphire
  • Coral
  • Demantoid Garnet
  • Dendritic Agate
  • Diamond
  • Druzy Azurite
  • Emerald
  • Enstatite
  • Fire Agate
  • Fire Opal
  • Fluorite
  • Fossil Coral
  • Garnet
  • Golden Beryl
  • Grandidierite
  • Grossularite Garnet
  • Hawk's Eye
  • Hematite
  • Hemimorphite Druzy
  • Hessonite Garnet
  • Hiddenite
  • Howlite
  • Idocrase
  • Imperial Topaz
  • Iolite
  • Jade Gemstones
  • Jadeite
  • Jasper
  • Kornerupine
  • Kunzite
  • Kyanite
  • Labradorite
  • Lapis Lazuli
  • Larimar
  • Malachite
  • Malaya Garnet
  • Mali Garnet
  • Maw-Sit-Sit
  • Moonstone
  • Morganite
  • Moss Opal
  • Mother of Pearl
  • Mystic Quartz
  • Mystic Topaz
  • Nuummite
  • Obsidian
  • Opal
  • Opal Doublet
  • Opal in Matrix
  • Pearl
  • Peridot
  • Pietersite
  • Prehnite
  • Pyrite
  • Pyrope Garnet
  • Quartz
  • Quartz Cat's Eye
  • Quartz With Marcasite
  • Rainbow Moonstone
  • Rainbow Pyrite
  • Rhodochrosite
  • Rhodolite Garnet
  • Rhodonite
  • Rose Quartz
  • Ruby
  • Ruby in Fuchsite
  • Ruby-Zoisite
  • Rutile Quartz
  • Sapphire
  • Scolecite
  • Seraphinite
  • Serpentine
  • Sillimanite
  • Sillimanite Cat's Eye
  • Smithsonite
  • Smoky Quartz
  • Snowflake Obsidian
  • Sodalite
  • Spectrolite
  • Spessartite Garnet
  • Sphalerite
  • Sphene
  • Spinel
  • Star Diopside
  • Star Garnet
  • Star Gemstones
  • Star Lemon Quartz
  • Star Moonstone
  • Star Rose Quartz
  • Star Ruby
  • Star Sapphire
  • Star Sunstone
  • Strawberry Quartz
  • Sugilite
  • Sunstone
  • Tanzanite
  • Tiger's Eye
  • Tiger's Eye Matrix
  • Topaz
  • Tourmaline
  • Tsavorite Garnet
  • Turquoise
  • Variscite
  • Zircon
Main Categories
  • New Arrivals
  • Gemstone Lots
  • Calibrated Gemstones
  • Gemstones By Piece
  • Top Grade Gems
  • Matching Pairs
  • Cabochon Gemstones
  • Drilled Gems, Briolettes and Beads
  • Birthstones
  • Gemstone Carvings
  • Fancy Gemstones
  • Star Gemstones
  • Unheated Sapphire
English speaking customer support only

Toll Free - USA & Canada only:
1-800-464-1640

International:
+66-39303404

Save Money
No shipping Fees for Additional Items!
$8.90 Worldwide Shipping

Update Translation
 
Current Value
New Value
GemSelect Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
Size and Weight

Gems are always measured in Millimeter (mm)

Dimensions are given as;
length x width x depth,
except for round stones which are;
diameter x depth

Select gems by size, not by weight!
Gem varieties vary in density, so carat weight is not a good indication of size

Note: 1ct = 0.2g

Size Comparison Chart