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

    1-800-464-1640

  • Change Language
  • USD
By Gavin Clarke Reviewed By Andreas Zabczyk Mar 18, 2008 Updated Feb 06, 2022

Semi-Precious Gemstones

The
The "Precious Four" Gems

The term semi-precious is used to refer to the entire world of colored gemstones, not including the four so-called precious gems, diamond, ruby, sapphire and emerald. The terms precious and semi-precious are actually no longer used in the gem trade, and the American Gem Trade Association (AGTA) officially requires that "Members should avoid the use of the term 'semi-precious' in describing gemstones".

This rejection of the term semi-precious is a way of recognizing the incredible diversity and rarity of many colored gemstones. One of the major changes in today's gem market is a growing consumer awareness of the vast range of colored stones. These days customers ask us about sphene and iolite and other previously obscure gem varieties just as often as they ask us about sapphire or emerald.

Rare Sphene Gems from GemSelect Natural Topaz at GemSelect Spinel Gems from Burma and Tanzania So the world of colored gemstones needs some new classifications to replace the outdated distinction between precious and semi-precious gems. None of the trade organizations have proposed a new schema. Yet, one is definitely necessary, since we need a way to explain to buyers why some gems are highly valued and others are not.

At the very least we need a classification for what we might call premium colored gems. These are gems that have excellent gemstone characteristics - hardness, durability, brilliance, clarity and color. In most cases they are also quite rare. These could be considered to be the new precious gems. This group would include not only ruby, sapphire and emerald, but also spinel, tanzanite, tsavorite garnet, demantoid garnet, alexandrite and the finer tourmaline.

Ametrine Gemstones at GemSelect Natural Chrome Diopside Another useful categorization is grouping gems that have good gemstone characteristics, but are widely available and very affordable. These include members of the quartz group - amethyst, citrine, ametrine, rose quartz, etc. - as well as topaz and the more common garnets. All of these stones have very good hardness (between 7 and 8 on the Mohs scale) and most have very good clarity. However, they are typically priced at well under $10 per carat.

Top Tsavorite Garnet at GemSelectThis still leaves forty or more varieties of fascinating gems to explore. Gemologists have useful ways to categorize them, but the market has a hard time classifying them, except by the term "colored stones". These gems include andalusite, diopside, fluorite, sphene, kyanite and moonstone. Each has its own unique colors and gemological characteristics. As they become better known, connoisseurs seek out the finest examples of each variety, so that the very best peridot and rarest rhodolite specimens become premium gemstones.

STAY IN TOUCH
*You're signing up to receive GemSelect promotional email.
Partners and Trust Payment options

Switch to Mobile Version

Privacy Notice © 2005-2023 GemSelect.com all rights reserved.

Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited.

472

More Shapes
Popular Gemstones
  • Sapphire
  • Emerald
  • Ruby
  • Aquamarine
  • Zircon
  • Opal
  • Topaz
  • Tourmaline
  • Garnet
  • Amethyst
  • Citrine
  • Tanzanite
All Gemstones (145)
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 Slice
  • Ametrine
  • Ammolite
  • Andalusite
  • Andesine Labradorite
  • Apatite
  • Aquamarine
  • Aventurine
  • Azotic Topaz
  • Azurite
  • Black Opal
  • Bloodstone
  • Boulder Opal
  • Carnelian
  • Cat's Eye Apatite
  • Cat's Eye Aquamarine
  • Cat's Eye Gemstones
  • Cat's Eye Moonstone
  • Cat's Eye Opal
  • Cat's Eye Scapolite
  • Chalcedony
  • Charoite
  • Chocolate Opal
  • Chrome Diopside
  • Chrysoberyl
  • Chrysoberyl Cat's Eye
  • Chrysocolla
  • Chrysoprase
  • Citrine
  • Color Change Gemstones
  • Color-Change Diaspore
  • Color-Change Fluorite
  • Color-Change Garnet
  • Coral
  • Demantoid Garnet
  • Dendritic Agate
  • Diamond
  • Druzy Amethyst
  • Druzy Azurite
  • Druzy Citrine
  • Druzy Variscite
  • Emerald
  • Enstatite
  • Fire Agate
  • Fire Opal
  • Fluorite
  • Fossil Coral
  • Garnet
  • Golden Beryl
  • Grandidierite
  • Grossularite Garnet
  • Hawk's Eye
  • Hematite
  • Hemimorphite
  • Hemimorphite Druzy
  • Hessonite Garnet
  • 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
  • Mother Of Pearl
  • Mystic Quartz
  • Mystic Topaz
  • Nuummite
  • Obsidian
  • Onyx
  • Opal
  • Opal Doublet
  • Opal In Matrix
  • Pearl
  • Peridot
  • Pietersite
  • Prehnite
  • Pyrite
  • Pyrope Garnet
  • Quartz
  • Quartz Cat's Eye
  • Quartz With Hedenbergite
  • Quartz With Marcasite
  • Rainbow Moonstone
  • Rainbow Pyrite
  • Rhodochrosite
  • Rhodolite Garnet
  • Rhodonite
  • Rose Quartz
  • Rubellite Tourmaline
  • Ruby
  • Ruby In Fuchsite
  • Ruby-Zoisite
  • Rutile Quartz
  • Sapphire
  • Scapolite
  • 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 Moonstone
  • Star Rose Quartz
  • Star Ruby
  • Star Sapphire
  • Strawberry Quartz
  • 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:
+66-39609697

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