The Gemmological Association of Australia

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The Gemmological Association of Australia

• Tasmania Division

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Diamond..

• The worlds most popular gemstone.
• Comes in all colours.
• Contrary to belief diamonds are not rare.
• They are the hardest of gems.
• Greatest amount by volume comes from Australia.

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Diamond..
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Diamond..
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Diamond..
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Beryl..

• A family of gems including emerald, aquamarine,
  heliodor and morganite.
• Fine gems are rare.
• Brittle and soft. (Hardness of 7 ).
• Desirable and expensive.

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Beryl..
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Beryl..
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Quartz..

• Silica crystalline gem.
• About 12 of the earths crust is quartz.
• Used for gems and carving.
• Includes rock crystal, amethyst, citrine,
  ametrine, smoky quartz and rose quartz.

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Quartz..
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Quartz..
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Agate..

• Silica (quartz) gem.
• Cryptocrystalline variety.
• A multicolored chalcedony having an infinite
  variety of patterns.
• Found in all parts of the world.
• Prime specimens come from Brazil Australia.

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Agate..
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Agate..
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Agate..
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Opal..

• Opal is also a silica gem.
• Opal has a high water content.
• Soft (hardness 4-5).
• Sold as solid doublet triplet.
• Australia supplies 95 of the worlds opal.

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Opal..
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Opal..
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Jade..

• The jade family includes nephrite and jadeite.
• It comes in many colours.
• Toughness is its strength.
• Used extensively for carving.
• Valued highly by many ethnic peoples.

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Jade..
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Other gems..

• The criteria for defining a gem.
• Beauty.
• Durability.
• Rarity.
• Gems may have one, two or all three qualities.

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Fascinating..
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Scintillating..
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Crowning..
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Radiating..
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Alluring..
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Ending..
Courtesy Boyd Sweeney FGAA Tasmania Division
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Thank you..

• We trust you enjoy your stay with us