Diamond: meaning, properties and lore

The mineral

Diamond's carbon is the same element found in charcoal and lampblack, yet its arrangement gives it a limpid, colourless quality and strong light refraction, which is usually traced to its crystal structure. As the only gem composed of a single element, it is typically about 99.95 percent carbon, with trace elements making up the rest.¹²³

It is much harder than graphite, which also contains only carbon. Obsidian flakes will not scratch a genuine diamond.^67893410211

Diamond has a density of 3.52 g/cm3 and a specific gravity of 3.52 (+/-0.01), which is 56 percent higher than the density of graphite. Its refractive index is 2.42 and it shows no birefringence. Genuine diamonds are heavier than imitations, so weighing a stone is a way of testing it.¹²¹⁰¹¹

Diamond's carbon atoms are bonded in essentially the same way in all directions. The most common shape for rough gem-quality diamond is the octahedron, which looks like two pyramids back to back. Its unique optical and physical properties give it adamantine luster, the highest possible luster of any transparent gemstone.¹⁰²

Diamond forms under high temperature and pressure. Graphite is the stable form of carbon at the earth's surface, while diamond is a denser form of carbon that needs great confining pressure. Most diamonds crystallize at depths of 150 to 200 km and temperatures of 900 to 1300 degrees Celsius, at the base of cratons. Diamond growth in the mantle is mostly metasomatic, with carbon-bearing fluids invading host rocks.^78102312

Kimberlites are the deeply derived magmas that carry diamonds to the surface, and they were named after the town of Kimberley. Volcanic activity transported diamonds in magma, forming kimberlite pipes, and erosion freed some rough diamonds into riverbeds and silt. Diamonds are found in rock, alluvial deposits, glacial tills and kimberlite pipes.¹²⁶³

Diamonds are colourless or faintly tinted in most gem use, and colourless stones are scarce, with most showing yellow or brown tints. Diamonds come in brown, yellow, red, pink, blue and green, and blue, green and red are the rarest. Some trace elements can influence colour or crystal shape. Nitrogen is the most abundant impurity in natural diamonds.^13314212

Diamonds are mined in South Africa, the Democratic Republic of the Congo, Botswana, Russia and northern Canada, and India, Brazil, Australia and Canada are also among sources. Brazil became an important source in the early 1700s, with stones found in gravels of the Jequitinhonha River in Minas Gerais. Diamonds in Botswana lie in the typically hot, semi-arid eastern region of the country.⁴³⁵

History and lore

Pliny the Elder, writing in ancient Rome, called diamond the most valuable of precious stones and of all things in the world. In his Natural History he wrote that a true diamond cannot be harmed by the force of hammer and anvil, and he listed diamonds among the costliest products drawn from the earth's interior. He also noted that diamond can be worked with a diamond point, unlike some stones that cannot be engraved with iron tools.^12531511

The name diamond comes from the Greek word adamas, which means invincible. Theocritus, who flourished around 228 B.C., called Pluto the adamas in Hades, using the word to express invincible hardness. The author of The magic of jewels and charms thought adamas first denoted a hard metallic substance before the Greeks applied the name to the diamond because of its extreme hardness. In Sanskrit the diamond is called vajra, which also means lightning.⁹⁴²³¹⁶

The Hebrew word shamir occurs three times in the Old Testament and in the first passage is translated diamond in the Bible. The author of The magic of jewels and charms holds that shamir most probably signifies a variety of corundum, since the Hebrews were almost certainly not familiar with the diamond. Cazwini's cosmography relates an Arab legend in which shamir was used by Solomon to dress stones for the temple.¹⁶

The Diamond was worn by the high priest in the breastplate of Judgement on the Ephod, as recorded in the book of Exodus. Lapidaries said that this Diamond would turn black if the Jews had sinned against God. Boetius wrote that a well-polished diamond without fault, of the weight of a peppercorn, is worth ten Florens or Crowns.¹⁵

Diamonds were gathered from rivers and streams in India, where the stone's use as a gem began, and some historians estimate that India was trading in diamonds as early as the fourth century BC. Diamonds were traded and coveted by royalty and the wealthy. By the 1400s they were becoming fashionable accessories for Europe's elite, having reached Western Europe via caravans to Venice's medieval markets.⁴⁵

Diamond was believed to ward off the evil eye, according to an anonymous second-century poet, and it was believed to be an antidote to poison and to provide protection against the plague. In the Middle Ages the diamond was linked with the moon as a white stone, though it was often regarded as the gem of the sun. Jean de la Taille de Bondaroy's poem to Marguerite de Valois said the diamond came from gold and from the sun.⁴³¹⁷

Napoleon gave a necklace of 234 diamonds to his wife when their son was born in 1811, and the first diamond engagement ring on record was given by Archduke Maximillian of Austria to Mary of Burgundy in 1477. Diamond mining expanded with the opening of the Argyle mine in Australia in 1983. The discovery of diamonds in Kimberley, South Africa, in 1866 marks the start of the modern diamond market.⁹⁴⁵

Birthstone, zodiac and chakra links

On almost all modern birthstone lists, diamond is recognized today as the birthstone for April, as presented by the Gemological Institute of America in its birthstone guide. Diamond is also the gift of choice for the 60th and 75th wedding anniversaries, and the 60th wedding anniversary gemstone is diamond in the GIA anniversary gemstone list.^1025438

Crystal practitioners say diamond is strongly associated with the zodiac sign Aries and the planet Venus, a link that is modern and that practitioners make. Crystal practitioners also make a modern link between diamond and the seventh (Crown) chakra, which is traditionally given in that practice.¹⁸

What crystal practitioners say

Crystal practitioners associate diamond with the mind and spirit, and those who write on this stone believe it enhances spiritual clarity and higher consciousness. Diamond is also believed to impart endurance and courage when facing life's challenges. Believers held that, like other gems, diamond could change in lustre according to the health or thoughts of the wearer.¹⁸¹⁷

Practitioners describe diamond as a powerful energy amplifier that intensifies other crystals and strengthens intentions. Believers treat it as an unchanging symbol of love and commitment in marriage.¹⁸⁸⁴⁷

Crystal practitioners advise that users cleanse diamond regularly. Users are advised to place it in sunlight or to use sound vibrations such as singing bowls. Practitioners say the stone is believed to cleanse negative energies and emotional blockages, while the mineral claims state that sunlight can fade some coloured stones.¹⁸

Users are advised to place diamond on the Crown Chakra during meditation while visualizing white light, according to crystal practitioners. Meditation with the stone is associated with clarity and spiritual focus in this practice. Believers thought carrying a diamond would provide strength, beauty, and happiness, and other potential benefits include balance, clarity, and abundance.¹⁸³

What testing has found

Crystal practitioners claim that crystals have effects on the body and mind, and researchers have tested those claims. Edzard Ernst concluded in his analysis of 150 complementary and alternative treatments that there are no rigorous trials testing the therapeutic value of crystal healing. Ernst states that scientific proof of any positive effect of crystal healing beyond a placebo effect does not exist.¹⁹

A 2001 double-blind study by Chris French tested crystal healing with 80 participants meditating with either a real quartz crystal or a fake glass crystal. Participants could not tell the real crystals from the fake ones, and they felt effects such as warmth, tingling or well-being that they had been primed to expect, which indicated a placebo effect only.²⁰¹⁹

Some researchers say crystals likely do not directly act on physical and psychological woes but may have indirect benefits explained by the placebo effect. Ted Kaptchuk, a Harvard Medical School professor, argues that discarding all placebo effects diminishes knowledge of important dimensions of health care.²¹

Rigorous scientific research into crystal therapy is lacking, and few studies have compared it to other therapies, so the scientific community remains skeptical. Permutt, a crystal practitioner, says there is no proven link between crystals and the body. GIA uses scientific matching to confirm the origin of stones, and knowledge of diamond has grown through research by geologists and mineralogists since the twentieth century.²¹⁶⁵