Diamond (Gemstone)

Diamond is an allotrope of carbon. It is the hardest known natural material and the third-hardest known material after aggregated diamond nanorods and ultrahard fullerite. Its hardness and high dispersion of light make it useful for industrial applications and jewelry.
Diamonds are specifically renowned as a material with superlative physical qualities; they make excellent abrasives because they can be scratched only by other diamonds, Borazon, ultrahard fullerite, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. Approximately 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion, and about 100,000 kg (220,000 lb) are synthesized annually.
The name diamond derives from the ancient Greek adamas (αδάμας; “invincible”). They have been treasured as gemstones since their use as religious icons in ancient India and usage in engraving tools also dates to early human history.[3][4] Popularity of diamonds has risen since the 19th century because of increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns. They are commonly judged by the “four Cs”: carat, clarity, color, and cut.
Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes, which brought to the surface the diamond crystals from deep in the Earth where the high pressure and temperature enables the formation of the crystals. The mining and distribution of natural diamonds are subjects of frequent controversy such as with concerns over the sale of conflict diamonds (aka blood diamonds) by African paramilitary groups.

Blue Diamond

The blue diamond pictured is a beautiful bright stone, we do not know the correct name for the nearest colour, so if anyone out there can suggest an accurate description, we would appreciate your feedback. Natural fancy blue diamonds are extremely rare and expensive. We rejected a number of other blue diamonds for various reasons, some had a sea-green overtone, others were not as bright, probably due to having slightly imperfect proportions, please read our Diamonds - Cut page if you do not know the importance of proportion. Some people might think that if they wanted a blue stone they could buy a sapphire, and they would be quite right, although this is a very unimaginative way of thinking. It would be very difficult to find a sapphire as bright and attractive as our diamond, and even if it were possible to find a sapphire as intense and as sparkly, it would be very expensive. Also, although sapphires are very hard, they are nowhere near as hard as diamonds.

jewellry

Anticlastic forged sterling bracelet.In creating jewellery, gemstones, coins, or other precious items are often used, and they are typically set into precious metals. Alloys of nearly every metal known have been encountered in jewellery -- bronze, for example, was common in Roman times. Modern jewellery usually includes gold, white gold, platinum, palladium, or silver. Most American and European gold jewellery is made of an alloy of gold, the purity of which is stated in karats, indicated by a number followed by the letter K. American gold jewellery must be of at least 10K purity (41.7% pure gold), (though in England the number is 9K and is typically found up to 18K (75% pure gold). Higher purity levels are less common with alloys at 22 K (91.6% pure gold), and 24 K (99.9% pure gold) being considered too soft for jewellery use in America and Europe. These high purity alloys, however, are widely used across Asia, the Middle East, and Africa.[citation needed] Platinum alloys range from 900 (90% pure) to 950 (95.0% pure). The silver used in jewellery is usually sterling silver, or 92.5% fine silver.