Not only is diamond the hardest, best heat conducting, hottest melting element, it also is the most dense. Its atoms are closely packed more than any other substance on the planet. Diamonds are used for many things other that jewelry such as abrasives as well as a heat conductor. .
Diamonds are found in South Africa, India, Brazil, Russia, Australia and in Arkansas. Some of the most famous diamonds are not colorless. For example, the Hope Diamond was a diamond of Titanic proportions (no pun intended). It was discovered in India and is a deep indigo blue color. It has been said that it was used to adorn the statue of a Hindu god. It is also reported that people who owned this diamond used to encounter great deals of bad luck. It was passed around from owner to owner until the Smithsonian Institute bought it in 1958. The longest private owner of the Hope Diamond was Evalyn Walsh McLean who owned it for 36 years. .
Emerald is the birthstone for the month of May and is one of the world's most popular colored gemstones. The name emerald comes from the French word, esmeraude, which means green gemstone. Fertility and childbirth were symbols that emeralds were thought to bring to wearers. Emeralds are beryllium aluminum silicates that achieve a hardness of 7.5 to 8 on the Mohs scale. The green color comes from the element chromium. Emeralds are one of the only gems where flaws or inclusions are acceptable. These flaws or inclusions are sometimes referred to as the garden within the emerald. Sometimes there are other crystals embedded in the emerald or there are gas bubbles that have been trapped. It is a rare event that an emerald grows to a large size without any imperfections, so large clear emeralds are always highly valued compared to those with inclusions. The main country where emeralds are found is Colombia. There are about 150 mines in the country today. Some gemologists can tell where an emerald came from due to its color and clarity.