How Jewellery Works?

One small diamond can set any one back by a huge amount of cash! But I never ever knew the cost that is involved in the mining of a Diamond. Have you ever thought about the processes involved in making a diamond.
All we know is go to a Jewellery store, look at a Diamond that's a beauty and purchase it. Recently I came across a site called www.caratlane.com, the site was good. What was interesting was the education they had on their site. It was about how and why diamonds are priced differently. How they are evaluated on various parameters. The kind of stuff I was interested to know, and it was some kind of news to me that there were, Pink, Blue and fancy coloured Diamonds.
Something else I recently got to know is that for obtaining a Diamond of 1 Carat (2mg or .2gms) they need to mine around 100 -300 tonnes of rock. The processes must be huge and very expensive.
And all this began as I was looking at gifting my wife a diamond pendant for her. I had a limited budget and had to take a decision based on the available options.
Will continue this again....