Sources of information - Internet
Diamond has many unequaled qualities and is very unique among minerals. It is the hardest known substance, it is the greatest conductor of heat, it has the highest melting point of any substance (7362° F or 4090° C), and it has the highest refractive index of any natural mineral. Diamond is number 10 on the Mohs scale, and is 40 times harder than Corundum, which is number 9 on the Moh's scale. It also has the most dense atomical configuration of any mineral, and is transparent over the greatest number of wavelengths. Because of heat conduction, Diamonds are cold to the feel at or below room temperature. When heated, a Diamond will remain hot long after the heat source is removed.
Diamonds are the world's most popular gemstones. More money is spent on diamonds than on all other gemstones combined. Diamonds are just carbon! Each carbon atom in a diamond is surrounded by four other carbon atoms and connected to them by strong covalent bonds. This simple, uniform, tightly-bonded arrangement yields one of the most durable substances known.
Diamonds are not native to Earth's surface. Instead they form at high temperatures and pressures that occur in Earth's mantle about 100 miles down.
Most of the diamonds that have been discovered were delivered to Earth's surface by deep-source volcanic eruptions. These eruptions begin in the mantle and on their way up they tear out pieces of mantle rock and deliver them to Earth's surface without melting. These blocks from the mantle are known as xenoliths. They contain diamonds that were formed at the high temperature and pressure conditions of the mantle.
All gem quality diamonds are graded using four basic parameters – the four Cs of Connoisseurship: Color, Cut, Clarity and Carat weight.
Color: Most gem quality diamonds range from colorless to yellow. The most highly regarded stones are those that are completely colorless. Most industrial-grade diamond is black in color due to impurities.
Cut: The quality of workmanship in a diamond has a large impact upon its quality. Ideal stones are perfectly polished to be highly reflective and emit a maximum amount of fire.
Clarity: The ideal diamond is free from internal flaws and inclusions (particles of foreign material within the stone).
Carat: Diamonds are sold by the carat (a unit of weight equal to 1/5th of a gram or 1/142nd of an ounce). Small diamonds cost less per carat than larger stones of equal quality. This is because very small stones are very common and large stones are especially rare. A handy formula for calculating the approximate carat size for emerald cut diamonds is length x width x height x 0.0100 where the units are millimeters
The co-ordinates will take you near the corner of Bond Street and Piccadilly near where you will see several posh rock merchants and some fine examples during the daytime - at night they may have been removed from the windows. Many of the windows do still have pictures of diamonds in them.
To claim this cache please email or msg the owner through their profile the answers to the following questions
1. Outside of one very well known Diamond Merchant/Mining company you will see a Diamond on the step. What is its length and width in centimeters.
2. Assuming the height of the diamond is 0.2 centimeters and it is a emerald cut diamond - how many carats is it?