The Sunday Mail
Maison Phiri
Diamonds are rare stones that exist in their natural state either in kimberlite or lamproite pipes that extend into the upper mantle of the geoid.
They are covalent bonds of carbon atoms and this gives them some particularly good physical characteristics that make them highly sought gem material.
A lot of imitations and synthetics are being manufactured to try and emulate the diamond value, but this makes it even worse. Natural diamonds become more and more sought after, as the natural reserves die down.hey are covalent bonds of carbon atoms and this gives them some particularly good physical characteristics that make them highly sought gem material.
In Zimbabwe, we have pipes in Zvishavane being exploited by Riozim (Murowa). A lesser operation has since receded its operations in Beitbridge (River Ranch). Various projects are establishing, some falling off along the road but the major emphasis goes to Marange diamonds (Chiadzwa).
It is itself an example of a secondary deposit, being alluvial. There are quite some particular characteristics that dog the Marange diamonds, especially when it comes to pricing as we shall see in this writing.
There are four basic Cs which are the skeleton for a diamond price. Every gemologist will use these. A few extrapolations may provide for the value of a rough diamond. However, it is more accurate to define the price of a cut diamond than a rough diamond. Hence it takes a lot of skill for someone to be able to price a rough diamond.
More often than not, rough diamond pricing is actually a practice made to try and reach a basis for negotiations. This explains why sellers may readily opt for a tender rather than a direct sale. One of the Cs is explained here.
Clarity
The more clear a diamond is, the better the price. So whatever impedes the passing of light through the diamond reduces its price. These impediments are divided into two categories:
Inclusions
These are the most important impediments and are a cause for worry when they are readily visible using the naked eye. Inclusions are anything internally in the stone that obstructs light. Whilst most of us are used to sparkling diamonds, the truth is that more than half the world diamond produce cannot meet that standard of “sparkling”.
This is especially so for alluvial diamonds which may have been subjected to metamorphism.
I do speculate that the Marange diamonds are a result of magmatic emplacement first, then onset of metamorphism and tectonics with subsequent denudation and secondary emplacement in Marange. But anyway that is what it is, speculation.
It just gives you an idea of how sparkling an alluvial metamorphosed stone in Marange may be, although each diamond has its own uniqueness.
Blemishes
Women will know more about blemishes, after being the major consumers of cosmetics. Well, the unfortunate part is that we cannot put cosmetics on diamonds, or can we?
For now I can tell you that any cosmetics that have been attempted on a stone has done nothing but reduce its price, so cosmetics are no guarantee for a price increase.
Blemishes refer to any surface marks or irregularities that assist in blocking the entrance and exit of light through a diamond. For this reason, always clean your diamond with a soft cloth before analysing the clarity.
Grading clarity
All laboratories have a way of grading clarity and the grading should be synonymous of the price index you intend to use. The position, depth and colour of an inclusion contribute to the effect of the inclusion on the grading. Conventionally, small inclusions in the edges of a cut diamond may not necessarily block the pathway of light so this may not down grade the clarity.
However, an inclusion in the centre of the stone is a big no no!
Next time you buy a diamond, ask for a 10x loupe and look through your stone.
If you see multiple imperfections confront your seller for a discount. It’s always good to have a diamond ring, and it’s not that expensive as myth says.
Maison Phirib(MBA, BSc, I.G.I-G.G, D.G, CSTG, HODTS). He writes in his personal capacity. Feedback: [email protected]
