Chemical formula: aluminum oxide with chromium, Al2O3
Color: various shades of red
Mohs scale hardness: 9
Specific gravity: 3.97-4.05
Refractive index: 1.76-1.77
Jewish tribe: Reuben
Planet: the Sun
Hindu chakra: Anahata – the fourth primary chakra representing the heart
Origin of the Name
The name "ruby" is of Latin origin – "rubrum" – meaning red.
Rubies in Judaism
"Fashion a breastplate for making decisions – the work of a skilled craftsman. Make it like the ephod: of gold, and of blue, purple and scarlet yarn, and of finely twisted linen. It is to be square – a span long and a span wide – and folded double. Then mount four rows of precious stones on it. In the first row there shall be a ruby, a topaz and a beryl; in the second row a turquoise, a sapphire and an emerald." (Exodus 28:15-18).
The Ruby is associated with the red stone of the Hoshen breastplate, a ceremonial piece worn by the high priest of the ancient Israelites. Among the 12 Hoshen stones, it represents the Tribe of Reuben.
There is no actual proof that the modern ruby is indeed the Hoshen gemstone: its etymology suggests that the red stone inlaid in the Hoshen breastplate was actually carnelian – a red gem which archeological findings have establish was common in ancient times.
The correlation between red gems and rubies can be traced back to the 10th century, in a Latin translation of the Bible by Luca ben Costa.
The Midrash also mentions the name ruby, but it is attributed to what we now know as corals: "(…) and this stone is called rabin, it grows in the sea… and is as red as blood."
|Ruby and Diamond Ring|
Rubies have been hailed as having magical healing powers since ancient times, and were considered to bestow wisdom and promote wealth. Ancient mid-eastern practices called for ruby flakes or powder to be applied to open flesh wounds, in an effort to gain courage and wisdom.
The rarity of rubies in ancient times turned them into a symbol of power and sovereignty. The Indians believed rubies conducted heat, and that placing them in water would bring the water to a boil.
Rarity: though similar in composition, rubies are far rarer than sapphires, and high quality rubies may fetch higher prices than diamonds. Graff Jewelers of London bought an 8.62 carat ruby for $3.6 million at a 2006 Christie's auction – $425,000 a carat!
Asterism: when a ruby is cut a certain way, it disperses light in a unique star-shaped pattern. These rubies are called "Star Rubies", since the star shaped reflection – which can sometimes show up to 12 rays – stays the same regardless of the angle of the stone. One of the most famous star rubies is the Delong Star Ruby, which in on display at the
|Ruby and Diamond Necklace|
Hardness: a ruby's hardness is second only to that of diamonds. This trait, and their innate durability, has made rubies useful for mechanical timepieces. They are still used in the mechanical watch industry today.
Color: rubies appear in various shades of red, with dark "pigeon blood" being the most prestigious shade. Pigeon blood rubies are extremely rare, even among rubies themselves.
The Rosser Reeves Ruby: at 138.7 carats, the Rosser Reeves Ruby is biggest ruby in the world. Its origins are from
The Black Prince's Ruby: perhaps the most famous case of "mistaken gem identity", the Black Prince's Ruby is an egg-size gem weighing roughly 170 carats. It is set in the English Crown, and is one of oldest gems of the Crown Jewels. However, it is not a ruby – it is a spinel. The latter was mistaken for a ruby since until the 20th century all red gemstones were referred to as "rubies".
The Carmen Lucia Ruby: considered one of the biggest rubies in the world, the Carmen Lucia Ruby is a 23.1 carat Burmese ruby, set in a platinum ring with diamonds. It was donated to the Smithsonian's National Museum of Natural History by businessman and philanthropist Peter Buck in memory of his wife Carmen Lucia.
Rubies are mined in
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