Gems Identification

Ruby

These gemstones come from red conundrum in various shades; some are pink, some a blackish shade and some are paler. The ruby is considered a hot stone and is one of the most valuable precious gems. It is generally found in crystals of six-sided prisms; all rubies are translucent and suitable for use due to their wide range of colours and hardness.

A flawless ruby is smooth; it has a lustre, radiance and brilliance with a rich, red colour. Rubies are very expensive because they are pretty rare; large rubies are rarer, and therefore more expensive, than a large diamond. One can tell a good ruby by dropping it into some milk, if it is a good stone it will emit red rays in the milk; it should also have red rays in early morning sun and glow a little in the dark. The rarest shade of ruby is said to be similar to that of pigeons’ blood; a sort of deep red, velvety and rich, but without fire or sparkle.

Rubies are cut differently to diamonds because they don’t have the same brilliance and lack the diamond’s sparkle; the stone is polished and cut into a convex form, but is not faceted. This technique of cutting is used for rubies because it emphasises that colour of the gem.

A poor or blemished ruby has a depression, or a pale hint of colour; it may also have smatterings of white, black or honey-coloured dots.

Diamond

The diamond is one of two crystalline forms derived from the element carbon; diamond is number 10 (top) on the Moh’s scale of hardness.

1 (Talc)
2 (Gypsum)
3 (Calcite)
4 (Fluorite)
5 (Apatite)
6 (Orthoclase Feldspar)
7 (Quartz)
8 (Topaz)
9 (Corundum)
10 (Diamond)
Hardness of other common objects
Fingernail: 2.5
Copper penny: 3
Glass: 5.5

Diamond is a hot gem of white, yellow, red, pink, blue, green or black. The diamond is unique in that, unlike the other gems, it is prized for its lack of colour; the less colour it has, the more it is worth. Diamonds that are colourless, with a hint of blue or sprays of red and blue rays, are considered the best and are the most used variety in jewellery. Coloured diamonds are sometimes known as ‘fancy diamonds’.

Experts measure the quality of the stone in terms of clarity, the clarity of the stone refers to its imperfections; a perfect or ‘flawless’ stone has no visible imperfections under a x10 microscope magnification. A diamond is blemished if it has dots or has impressions of water drops.

The diamond’s refractive index is the highest of all the gems, its dispersions is very strong; if reflected in water a hexagonal or octagonal diamond shows all the colours of the rainbow.

A two-carat diamond will often be more than twice the cost of a one-carat diamond. The cut of a diamond is know as the ‘C’, this definition carries the most importance when valuing a diamond; the cutting determines the diamond’s beauty and brilliance. The best cutter will shape the diamond in such a way to lure the most amount of light into the stone, which is then reflected back out as sparkling brilliance. The cut of the diamond is more important by far than its size; a large diamond is less valuable than an expertly cut smaller one.

Diamonds are cut into round, oval, pear or emerald shapes. The round shape is called ‘brilliant’ because it reflects the most light. Cutting a diamond into an emerald, pear or oval shape can make the diamond appear larger than it actually is.

Pearl

Pearls come from certain molluscs; mainly the oyster or freshwater mussel, the pearl is organic but it is mostly comprised of mineral matter. Jewellery makers are fond of cultured pearls, where they are made artificially through interrupting the natural process, though it is impossible for most people to tell the difference between a natural pearl and a cultured one. Natural pearls are often ten times more expensive than cultured ones.

Like most gems, a pearl’s value is judged on colour, and comes in three different groups; white with creamy pink is the most sought after; black and various shades of grey; and coloured pears, which are mostly of freshwater origin. Pearls of the purest form are round and lustrous, though it is thought that the long and flat varieties also have curative powers.

A flawed pearl is broken, may have cracks or spots, and is dull in colour.

Emerald

The emerald is a rich variety of beryl; its colour is caused by the presence of chromium oxide. It is considered one of the hot stones and is also one of the most expensive. Its green colour ranges from that of grass to a deep velvety green.

A perfect emerald is transparent and smooth; it has radiance and brilliance and sprays bright rays.

A blemished emerald has a depression or cracks, lustrous but brittle; it may have black or yellow spots with a rough surface.

The emerald is softer than diamond, ruby and sapphire. They lack a lot of the brilliance of the other precious stones so that when they are cut they are crafted in a convex manner, which shows off its beautiful colour, where the emerald’s value sits.

Coral

A coral is a hard, calcareous, red, white or black skeleton of any of the various marine invertebrate animals; the type that form the Great Barrier Reef of the Queensland coast in Australia. A coral’s colour varies from shades of red to white and yellow. A good coral will be perfectly round or oval, have an opaque red colour, emit a sheen, and its surface should be smooth. It should also be unmarked by any holes or perforations.

An imperfect coral has white or black spots, a depression, a crack, a bend or a twist on its surface and will sometime have many hues.

Topaz

Topaz is found in granite rocks and is a silicate and fluoride of aluminium. It is transparent in appearance. It is thought of as a cold gem, it occurs naturally in a prismatic form with a pyramidal ending. It’s usually yellow, but it also comes in pink and blue shades.

A flawed Topaz has red dots, or a depression, or cracks.

Sapphire

Sapphires are the valuable blue variety of corundum, the same mineral that the ruby comes from. But, while rubies are always red, sapphires come in pink, orange, violet, green, yellow, and blue. It is thought of as a cold gem and has the same refractive qualities as the ruby. The highest quality blue sapphire will not change its colour when held up in front of an electric light bulb, lesser quality stones will show a paler blue tinge. The sapphire is smooth and transparent, soft to the touch, and reflects rays from within. Three crossed lines intersect each other in the middle; these are said to represent faith, destiny and hope, which is why some call it the ‘stone of destiny’.

A bad stone can have white lines upon it; it may be dull and opaque; or it may have a depression, or have more than one colour and be milky.

Zircon

Zircon is a common crystal that is tetragonal shaped, it appears in small prismatic forms both opaque and transparent. It has a resemblance of diamond and is thought of as a cold stone. This gem is naturally without colour and also reddish-orange, brownish-red, grey, violet-grey, or green. It changes to a bluish-white colour when it is subjected to heat, it is in this form that zircon is used as a gem.

Golden light should be seen reflected from this stone at a distance as a sign that it is good; it should also be transparent, soft to the touch with a radiant lustre.

A bad stone shows a light blackish-blue from a distance, has a flat body, lots of layers, may be dull and look like a piece of yellow glass.

Cat’s Eye

Cat’s Eye is a hard semi-transparent version of quartz, well used as a gem. It is considered a very hot stone with a milky iridescence in various shades from a cloudy yellow to a brownish-green colour. Its milky iridescent radiation of colours is what gives it its name. The purest form of Cat’s Eye has a yellowish radiance with a brilliant, white band.

A flawed Cat’s Eye has a depression, or spots, lines like a web, or a dull sheen.

Semi-precious stones that are used as substitutes for the above:

Opal

The opal occurs in various colours and is a mineral consisting of hydrous silica. The opal is not as hard or dense as quartz and good examples have an iridescent reflection of light. Using an opal is said to lift the consciousness into a higher spiritual awareness.

Tourmaline

A soft silicate of boron and aluminium that occurs in black, green, red, brown and white; the clear variety is used as a gem.

Amethyst

This spiritually cleansing stone contains traces of manganese, titanium and iron; the violet variety of quartz is used as a gem.

Garnet

A hard, vitreous silicate mineral that comes in a few varieties; most common of which to be used as a gem is a transparent deep red variety.

Aquamarine

A bluish-green stone with the hue of oceans from which it gets its name; this stone is the finest form of beryl and is transparent.

Bloodstone

This is a green type of quartz spattered with red blood-like specks made from the red jasper inside it.

Lapis-lazuli

This stone is a rich blue colour and made of lazurite and other minerals.

Agate

A semi-precious clear stone with many layers of different colours blended together.

Turquoise

This sky-blue mineral is thought to have the power to cleanse the World’s atmosphere and is also worn for protection.

Jade

A green stone favoured in parts of China; it is hard and either translucent or opaque, it is also sometimes veined.

Gypsum

A mineral, a hydrous sulphate of calcium that occurs in crystalline and solid form.

Smoky Quartz

A variety of crystal quartz that ranges in colour from light yellow to deep brown.

Onyx

A semi-clear, dark-green stone with veins of differing colours.

Carnelian

A variety of chalcedony that comes in various shades of red.

Jasper

An opaque dark red quartz that can be polished to give an elegant appearance.

Rock Crystal

Transparent quartz of either a colourless or shining white hue.

Moonstone

This is a translucent type of feldspar with a pearly sheen. It also has a glistening band inside that moves as the stone is turned.