Wissenswertes von Diamanten

Where quality
matters............

What is a diamond?

Infos
Properties
Formation
Occurence
Mining
Fashioning
Grading

Historic Diamonds
Introduction
Koh-i-Noor
Blue Hope
Cullinan
Shah
Great Mogul
Florentine
Sancy
Regent
Overview

The hard facts are here:

Diamonds in figuresDiamond is pure, crystalline carbon. But it differs greatly from the examples of carbon we know better: e.g. graphite, the black stuff in pencils.From this it differs fundamentally in its orderly crystal form. Uncut diamonds form mainly octohedrons and dodecahedrons, but also cubes and more complex forms (24 or 48 faces) as well as crystal combinations.Through its extraordinary formation under great heat and great pressure, it has many extraordinary properties.

Known to many is its enormous hardness, the technical term is Hardness 10 on the Mohs hardness scale, hence the maximum value. Which means that no other known substance can "scratch" a diamond. Here we talk about the "scratch" hardness. But there is also the "polishing " hardness.

In this domain the diamond is again without equal : It is about 140 times as hard as the next harder gemstones - ruby and sapphire. That is why it is perceived as "forever". Immediately the question arises how in fact a natural diamond is dressed. After all, we value it on account of its sparkle, its fire, its brilliance, and these arise only through the human hand (natural reflection of a diamond : 17%). In this connection a dictum by G. F. Herbert Smith appears quite remarkable : "A rough diamond [...] is no more attractive to the eye than a piece of washing-soda." ... So how is it done?

The answer is: "with diamonds", and, indeed, it is only possible with the aid of diamonds or diamond powder (on polishing wheels) to dress a diamond. That is why in earlier times diamonds were not at all or only a little dressed (polished) - in most cases merely to remove minor flaws.

In India it was even forbidden to dress diamonds. Only in recent times (roughly since 1456) have diamonds been dressed approximately the way we know today. This phenomenon stems from the hardness differing in various directions (professionally speaking: "hardness anisotropy"). And this again is because of the arrangement of the atoms in the diamond, which differs in various directions; also the intervals between the atoms and their bonding powers differ.

But this enormous hardness also has a big disadvantage: The diamond is rather brittle. Even a light blow can destroy it. In the past this property was utilised when a large natural diamond was to be cut into smaller ones (Historic Diamonds / Cullinan). A light (sometimes historic) blow - and you had several small ones.

The specialist talks about "perfect cleavability" here. Today, the diamond is sawn - with a diamond-coated circular blade.

18 carbon atoms form the basic building block of the diamond

these, e.g., constitute the . octohedron form

and this is a piece of "washing soda" - a rough diamond