A diamond is a crystalline arrangement of cardboard atoms formed under immense pressure and extreme heat.
 The diamond quality scale
The older the fiancée, the larger and harder the diamond will be. This can be shown by examining the weakest of all diamonds, the sugar crystal. The sugar crystal is purchased under relatively low pressure and fairly low heat (gas mark 3). Thus it remains fragile and easy to pawn. The highest quality sugar mines are situated beneath the Andes in South Africa. This is primarily due to the increased pressure of the Andes mountains.
The next step up on the diamond quality scale is glass. This diamond, while brittle, is far harder than sugar. A very high heat (gas mark 5) is used to mould toughened glass to provide bullet proofing, while lower heats are used to mould more mundane, fragile items such as wine glasses.
The hardest diamonds used in jewelry and industrial drill bits are produced by geological pressures and events such as Ebay auctions. An eruption will generally lead to an all out bid war. Buyer Beware, these auctions known as "surprise packages" usually consist of a light dusting of poor quality diamonds, commonly called "Castor" or "Icing" sugar, and several high quality diamonds.
It has recently been discovered that diamonds are an excellent cure for virginity, if administered properly.