Diamonds are the popular birthstone for the month of April and the mystical birthstone for the month of August.
Formula: C (pure carbon)
Crystal system: isometric
Crystal form: octahedra, dodecahedra, cubes, and combinations of these forms. Nearly all diamonds have been “cut” into faceted shapes for jewelry.
Diamond is the hardest mineral on earth; the hardest substance known. In the atomic arrangement of diamond, each carbon atom is linked to four equidistant neighbors, creating a close-knit, dense, strongly bonded structure--the source of its unsurpassed hardness and many other properties. It is formed deep in the mantle and is only brought to the surface via kimberlite pipes, lamprophyres, eclogites, and other rocks that originate deep within the mantle. It is also found in alluvial deposits, along with quartz, corundum, zircon, and other minerals, derived from such rocks, and in certain meteorites.
Crystals may be transparent, translucent or opaque, and range from colorless to black, with brown and yellow being the most common colors. Colorless or pale blue gemstones are the most often used in jewelry. Red and green have long been considered the rarest colors, but pure orange and violet are much rarer and much more valuable. Industrial diamonds tend to be gray or brown and are translucent to opaque. The color of diamonds can be changed by artificial exposure to intense radiation or by heat treatment; many of the "fancy" colored stones on the market today are a result of such treatments.
Diamond crystals are usually well-formed because of the highly uniform arrangement of their component carbon atoms, occurring as octahedrons and cubes with rounded edges and slightly convex faces. Its name from the Greek adamas, meaning "I take" or "I subdue", a reference to its superior hardness. In addition to its crystalline form, diamond occurs in two other forms: bort, or boart, is an irregular or granular black diamond; carbonado occurs as microcrystalline masses. Most diamonds come from two rare kinds of volcanic rocks, lamproite and kimberlite, but they are much older than the rocks in which they are found. The right conditions for diamond to crystallize occur in the mantle of the Earth, generally more than 95 miles deep, below ancient continental masses. Kimberlite magmas originate particularly deep and, when they erupt, diamonds and other fragments sourced from mantle rocks are forced up to Earth's surface. As magma cools, it forms a steeply conical pipe-shaped body. Most natural diamonds are mined from these kimberlite pipes.
The world’s love of diamonds had its start in India, where diamonds were gathered from the country’s rivers and streams. India's Golconda field having been worked for centuries--possibly as early as 800 BC. Some historians estimate that India was trading in diamonds as early as the fourth century BC. The country’s resources yielded limited quantities for an equally limited market: India’s very wealthy classes. Gradually, though, this changed. Indian diamonds found their way, along with other exotic merchandise, to Western Europe in the caravans that traveled to Venice’s medieval markets. By the 1400s, diamonds were becoming fashionable accessories for Europe’s elite.
In the early 1700s, as India’s diamond supplies began to decline, Brazil emerged as an important source after the Spanish conquest. Diamonds were discovered in the pans of gold miners as they sifted through the gravels of local rivers. Once it reached its full potential, Brazil dominated the diamond market for more than 150 years.
While sources changed, the diamond market experienced its own evolution. The old ruling classes—diamonds’ biggest consumers—were in decline by the late 1700s. Political upheavals like the French Revolution led to changes in the distribution of wealth.
The 1800s brought increasing affluence to western Europe and the United States. Explorers unearthed the first great South African diamond deposits in the late 1800s just as diamond demand broadened.
The story of the modern diamond market really begins on the African continent, with the 1866 discovery of diamonds in Kimberley, South Africa. Entrepreneur Cecil Rhodes established De Beers Consolidated Mines Limited 22 years later, in 1888. By 1900, De Beers, through its mines in South Africa, controlled an estimated 90 percent of the world’s production of rough diamonds. Today, the major gem diamond reserves are in Botswana, Australia, Russia, Congo, and Angola. Many of the South African diamond mines are worked out, and South Africa is no longer one of the top diamond-producing nations. Australia, Congo, and Russia are the main producers of industrial diamonds. Canada has several diamond mines in kimberlite pipes still to come to full production; once this happens, Canada will be producing at least 15-20 percent of the total world diamond output.
Going back to early history, diamonds were always used to engrave tools because of their hardness. Warriors in ancient Greece wore diamonds as the stones were thought to strengthen the warriors’ muscles and bring them invincibility. The power, hardness, and beauty of the diamond have been prized throughout history in many civilizations. The famous Persian poet Hafiz remarked that "the rainbow is confined in a diamond forever". In antiquity, a diamond was always thought to be a symbol of innocence and purity. Ancient Greeks thought that diamonds represented the tears of weeping gods. Ancient Romans thought diamonds were considered to be parts of the outer rings of stars, which had fallen to the earth.
The Renaissance Period was the first point in time when diamonds were used as engagement rings. They were thought to be a special gift, which represented the very ultimate gift of love. In 1477, this trend was started when Archduke Maximillian gave Mary of Burgundy a diamond engagement ring. This was a trend that was only popular among royalty and the very wealthy. Giving a diamond as an engagement ring did not actually become a standard until the De Beers marketing campaign started, during the 20th Century.