A Gemstone is usually defined as a highly attractive and valuable piece of cut and polished mineral that is used in jewelry.
We use the word Gemstone to describe any element, rock, mineral, crystal or organic material, that because of it’s beauty, rarity, usefulness or other properties has some value to mankind, either commercially, or personally.
What are we talking about?
Cabochon – A gemstone without facets that has a flat base and smooth, rounded edges. Informally known as a Cab.
Cleavage – The tendency of a crystal to split along definite crystalline planes to produce smooth surfaces.
Cluster – Dense agglomeration of crystals usually sprouting from the same base or matrix.
Coating – A thin layer of one mineral on the surface of another.
Dendritic – “Tree-like”. A crystal aggregate composed of branching skeletal or tree-like formations.
Doubly terminated – A crystalline gemstone with a complete termination at both ends.
Drusy – Aggregate composed of many small pointed crystals protruding from a cavity or base.
Face – An individual flat section of a faceted gemstone or natural crystal.
Geode – A hollow rock, often of igneous origin, that is filled or partially filled with crystals.
– Metallic or looking like polished metal.
– Sub-metallic or looking like dull or weathered metal.
– Non-metallic or not looking like a metal at all. This is divied into the following categories –
– Adamantine. Bright and sparkly, like a cut diamond.
– Resinous or looking like smooth surfaced plastic.
– Vitreous or Glassy, looking like clear or coloured glass.
– Pearly. Having the mother-of-pearl iridescence.
– Silky. Having many fine parallel fibers.
– Greasy or Waxy. Looking slippery and fatty, these stones are often also greasy to the touch.
– Dull or Earthy. These have little to no lustre or shine.
Microcrystalline – Composed of tiny crystals that cannot be seen with the naked eye. Jasper is a microcrystalline form of quartz.
Scepter – Where the top part of a prismatic crystal protrudes and is wider than the base.
Phantom growth – When a transparent crystal grows over existing crystal layers, leaving an impression behind. With multiple growth stops and starts, there is a possibility of more than one phantom in a crystal.
Tabular – Crystal habit describing a thin and often four-sided crystal or gemstone.
Translucent – Describing something that is able to transmit light but not fully.
Transparency – The quality of how a mineral lets light through. Minerals that can be seen thru are transparent.
Opaque – Describes substances that cannot be seen through and will not let any light through.
Twinning – Tendency of some crystals to intergrow in a distinct way or form to make specific, repeated patterns.
Minerals, crystals and gemstones all form in one of three ways, which can give you a clue to the identity of that hard to place stone.
Igneous – Igneous rocks are formed from the solidification of molten rock material.
Some well known Igneous Gemstones (prehnite,apatite,topaz,diamond,agate,amethyst,bloodstone,citrine,moonstone,tourmalines,labradorite,amazonite)
There are two basic types –
- Intrusive igneous rocks crystallize below Earth’s surface, and the slow cooling that occurs there allows large crystals to form. Examples of intrusive igneous rocks are granite, pegmatite and peridotite.
- Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include basalt, obsidian, pumice and tuff.
Sedimentary – Sedimentary rocks are formed by the accumulation of sediments and can include igneous as well as metamorphic “ancestors”.
Some well known Sedimentary Gemstones (calcite,aragonite,pyrite,hematite,milky quartz,gold,flourite,halite,amber,jet,pearl,agate,celestite)
There are three basic types –
- Clastic sedimentary rocks such as sandstone, siltstone and shale are formed from mechanical weathering debris.
- Chemical sedimentary rocks such as rock salt, iron ore, flint and some limestones, form when dissolved materials precipitate from solution.
- Organic sedimentary rocks such as coal, some dolomites and some limestones, form from the accumulation of plant or animal debris.
Metamorphic – Metamorphic rocks have been modified by heat, pressure and chemical processes, usually while buried deep below the Earth’s surface. Exposure to these extreme conditions has altered the mineralogy, texture and chemical composition of the rocks.
Some well known Metamorphic Gemstones (ruby,emerald,sapphire,jade,carnelian,tigers eye,jasper,lapis lazuli,turquoise)
There are two basic types –
- Foliated metamorphic rocks such as gneiss, schist and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.
- Non-foliated metamorphic rocks such as marble, quartzite and novaculite do not have a layered or banded appearance.
Choose one that’s right for you.
|Aries (The Ram)||Mar 21 – Apr 19||Fire||Mars||(Jasper), Bloodstone, Aventurine, Citrine, Emerald,
Hematite, Red Jasper, Kyanite, Obsidian, Red Tiger’s Eye
|Taurus (The Bull)||Apr 20 -May 20||Earth||Venus||(Sapphire), Green Aventurine, Dioptase, Emerald, Red Jasper, Picture Jasper, Kyanite, Orange Carnelian,
Rhodonite, Rose Quartz, Selenite, Red Tiger’s Eye, Blue Tourmaline
|Gemini (The Twins)||May 21 – Jun 20||Air||Mercury||(Agate), Apetite, Blue Lace Agate, Citrine, Emerald,
Yellow Jasper, Watermelon Tourmaline
|Cancer (The Crab)||Jun 21 – Jul 22||Water||Moon||(Emerald), Calcite, Moonstone, Orange Carnelian|
|Leo (The Lion)||Jul 23 – Aug 22||Fire||Sun||(Onyx), Citrine, Yellow Jasper, Picture Jasper, Labradorite,
Orange Carnelian, All Tiger’s Eye
|Virgo (The Virgin)||Aug 23 – Sep 22||Earth||Mercury||(Carnelian), Amazonite, Amethyst, Green Aventurine,
Mookaite, Snowflake Obsidian, Prehnite, Sugalite, Topaz
|Libra (The Scales)||Sep 23 – Oct 22||Air||Venus||(Peridot), Apetite, Bloodstone, Citrine, Kyanite,Lapis Lazuli,
Lepidolite, Moonstone, Prehnite, Rose Quartz, Blue Tourmaline
|Scorpio (The Scorpion)||Oct 23 – Nov 21||Water||Mars||(Beryl), Dioptase, Red Jasper, Mookaite, Labradorite, Malachite, Moldevite, Moonstone,
Black Obsidian, Smoky Quartz, Stibnite, Red Tiger’s Eye, Blue Tourmaline
|Sagittarius (The Archer)||Nov 22 – Dec 21||Fire||Jupiter||(Topaz), Yellow Calcite, Dioptase, Labradorite, Lapis Lazuli,
Obsidian, Smoky Quartz, Sodalite, Sugalite
|Capricorn (The Goat)||Dec 22 – Jan 19||Earth||Saturn||(Ruby), Flourite, Yellow Jasper, Picture Jasper. Malachite, Snowflake Obsidian, Smoky Quartz,
Stibnite, All Tiger’s Eye, Black Tourmaline, Green Tourmaline
|Aquarius (The Water Bearer)||Jan 20 – Feb 18||Air||Uranus||(Garnet), Amethyst, Angelite, Hematite, Mica|
|Pisces (The Fish)||Feb 19 – Mar 20||Water||Neptune||(Amethyst), Bloodstone, Blue Lace Agate, Yellow Calcite, Flourite|
In a crystal we have the clear evidence of the existence of a formative life-principle, and though we cannot understand the life of a crystal, it is none the less a living being.
— Nikola Tesla