Basics of Gemstones Explained

I have seen hundreds of websites related to gemstones in the last couple of years. On a majority of them, the information is either incomplete or just outright wrong. And, not surprisingly, diamonds are the most abused of them all. I hope what you are going to read now wipes out all the misinformation.

Before I start talking about different types of gemstones and throw technical jargons at you, let me explain certain basic facts and concepts.

Colour: Combination of tone (amount of lightness and darkness), hue (the spectral sensation like red or blue) and saturation (purity or dullness of colour). Colour is created by the light wavelengths a stone absorbs, transmits or reflects.

Transparency: Level of transmitting light. It varies from transparent, translucent to opaque. There are more categories in between.

Cutting Style: Shape or style of cutting. They include faceted (orange and blue stone in the logo), cabochons or cabs (the green and lavender coloured stones), tablets (square, rectangular shaped), cameo (usually found on shells), bead (any stone with a hole drilled), tumbled (rough stone ran through a tumbler to unshapern the edges, look at the opal).

Phenomena: Optical effects that are caused in a gemstone due to reasons such as it structure, growth pattern, inclusions, etc. I personally feel that phenomenal gemstones are cool. They are mostly made in cabs to bring out the phenomenon. Most of the times you see the phenomenon when you concentrate light on it. It is important for gemology because a lot of stones are categorized due to their phenomenon.

Now the different kinds of phenomena. I do not have pictures right now to show what exactly a phenomenon looks like but will definitely add it later.

Asterism: A star effect caused by light reflecting off minute needle like inclusions.
Adularescence: Billowy light caused due to diffraction, interference and diffusion.
Aventurescence: Colour spangling or glittering caused due to light reflecting off platelets in the stone. These platelets are natural.
Chatoyancy: This is the same thing as Cat's Eye. Just a technical term. It is also caused due to light relecting off minute parallel needle like inclusions.
Colour Change: A very cool effect that makes the stone change it's Colour in different light wavelengths.
Iridescence: Spectral colours present within or on the surface of a gemstone.
Labradorescence: This one's a tongue twister. It is a broad flash of single colour seen on the surface oflabradorite.
Orient: A form of iridescence seen on or below the surface of peral, cultured pearl or mother of pearl.
Play of Colour: The flashes of colour in opal.

Some terms that are often used.
Luster: It is the quality and quantity of light reflecting off a stone. It is classified into high, medium, low and sheen (sheen takes place just below the surface). Luster is important sometimes in gem identification because it indicates the stones hardness.
Dispersion: It is the break up of light into the rainbow (spectral) colours.
Hardness: The gemstone's resistance to scratching (and not chipping or breaking).
Toughness: The resistance to various chemicals.
Durability: The resistance to chipping and breaking.

Since we got that out of our way, let's talk about my favourite stone, the King of the Kings Diamond and certain important facts relating to it.

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