All through human history, gemstones have been highly valued for their beauty and rarity. People of many early civilizations also believed that gemstones possessed mystical powers and could have a positive or negative influence over circumstances.
Though it is hard to pin point exactly when gemstones were assigned to the twelve signs of the zodiac, it is a practice that is carried forth to this day.
However, a person's birthstone differs from their zodiac stone, and is related to the month of their birth. There are 12 birthstones that correspond to the 12 months of the year.
A popular opinion is that the root of these 12 stones stems from the usage of the 12 stones in Aaron's breastplate to symbolize the 12 tribes of Israel, mentioned in the book of Exodus in the Old Testament of the Bible.
While the list of birthstones has differed across cultures and times, the most widely followed birthstone list in the United States is the one that was released by the American National Association of Jewelers in 1912. However, this list is said to be formulated on the basis of availability, cost and popularity, and is thus considered a 'commercial' list.
Some stones have been included as they were more commercially viable than the original stone. Tanzanite was added to December by the American Gem Trade Association in 2002. While some people restrict themselves to using their birthstone, others wear a different stone each month to optimize the benefits they get from the stone during its month.
The mollusk coats the particle with layer after layer of a substance called nacre, eventually forming a pearl. Before the advent of pearl culturing, the stone was an extremely rare, expensive, and prized gem. For this reason, it is used as a metaphor to denote high quality or rarity.
Natural pearls that occur in the wild without any human intervention are very rare. To find one such pearl, several hundreds of pearl oysters or pearl mussels have to be opened. Called pearl hunting, it was the only way to obtain this precious stone in the past.
The modern way of obtaining pearls is through culturing, where a foreign particle, usually a bead is inserted into the oyster. The mollusk then covers the bead with a few layers of nacre, and in six months or more the newly formed pearl is removed.
Traditionally, pearls are white with shadows of iridescent pink, but the culturing process makes it possible to produce pearls of different shapes and hues.
While the pearls produced in the US satiate its domestic markets, freshwater pearls from China are sold all over the world. In recent times, China has been producing more Akoya pearls than Japan.
However, Japan maintains its position as a major pearl producer by buying pearls from China, which it processes or just sorts and matches, and sells overseas as Japanese pearls.
Button pearls are slightly flattened round pearls. The drop or pear-shaped pearls are usually referred to as teardrop pearls, and are frequently incorporated into earrings or pendants. Baroque pearls are usually irregular and often take on unique and interesting shapes.
Produced by the Akoya oyster, they were originally largely cultured in Japan, though in recent times, China has overtaken them in production. They are produced in a small size, between 6 to 8 cm, are usually round or near round, and are available in white and cream shades with silver or pink overtones.