Given that it is an organic gemstone, pearl is distinctive among birthstones. The only other birthstones are minerals, which are inorganic solids with crystalline structures and constant chemical compositions that only vary within certain bounds. The calcium carbonate mineral aragonite, which crystallizes in the orthorhombic system, is the component of the tiny, overlapping platelets that make up pearls. Although the pearl is composed of a mineral, it cannot be classified as a mineral because of its organic origin. The oldest instances of pearls have been found in rocks from the Triassic period in Hungary and the Cretaceous period in California, although all had lost their shine. Pearls have a rather long geologic history. The oldest pearls with shine have been discovered in southern England in Eocene-aged strata.
Another characteristic that makes pearl special is that it is perhaps the only gem material that can be used to make jewelry right away after being discovered. Before being put in jewelry, all other gems must be fashioned and polished, however inelegantly. Romans were huge fans of pearls, and Byzantine rulers treasured them. Robes and cloaks of the royalty may have been adorned with thousands of pearls.
Several species of bivalves (clams), which belong to the Phylum Mollusca, produce pearls in either salt or fresh water settings. A head, a foot, a visceral mass, and mantle lobes are all carried around by the mollusk’s body, which is made of a hard calcium carbonate (calcite or aragonite) shell. In the past, the marine bivalves Pinctada vulgaris and P. margaratifera, which were common in the Persian Gulf, provided the majority of the pearls used in the jewelry industry. The basin is between 15 and 20 meters deep, with the exception of its center, making the habitat perfect for these bivalves. The clams were found by divers who operated tiny boats with their crews. The pearl was cleaned of mud and other organic materials when it was found. The pearl divers sold their catch to merchants, who then shipped it to brokers in India, who used hydrogen peroxide to remove any blemishes. Most of the pearls were sold to merchants in Western Europe, primarily in Paris, after being size-sorted and graded.
Several types of clams that live in American rivers have been shown to contain fresh water pearls. In regions of the United States, the majority of them have been connected to Unio species, which are now the foundation of a fresh water cultured pearl business. When an irritant gets stuck between the bivalve’s mantle lobe and shell, pearls are created. The pearl is created by the bivalve secreting layers of aragonite platelets surrounding the irritant. If all goes according to plan, the pearl nucleus will detach from the shell and completely round itself in the mantle, growing into a loose, spherical pearl as a result. Pearly blisters form on the inside of the shell when the nucleus does not always detach from the shell. Although a pearl appears to have concentric, smooth layers in cross section, closer inspection reveals that these layers actually have an imbricate (brick wall-like) structure. A substance known as conchiolin, an organic cementing agent, holds these small plates together. When the surface is magnified, erratic lines that approximate topography features can be seen. The white light diffraction and interference created by the minute, overlapping calcium carbonate platelets give the pearl its iridescent appearance. The quantity and thickness of these platelets affect the pearl’s iridescence and orient. On the inside surfaces or inner walls of the mollusk shell, mother-of-pearl or nacre develops. The difference between mother of pearl and pearl is that the former is still a component of the mollusk’s shell, whereas the latter has separated from it.
Color, luster, iridescence, form, and size are a few of the elements that affect a pearl’s value.
The most sought-after pearls are large, spherical ones, and fine examples can fetch very high prices. The most popular pearl colors differ from region to region and culture to culture. Pure white or pure yellow pearls are generally universally despised, but cream rose and light rose colors are virtually universally adored. However, there are many tints in between that have different social standing around the world. Pearls that are oblong, teardrop-shaped, or flat typically sell for less money. Opaque pearls with low luster are less desirable than semi-translucent pearls with high brilliance. Iridescence and orientation are other crucial factors in pearl grading. A string of pearls is evaluated according to the aforementioned standards as well as how well the colors and shine of the individual pearls match as a whole.
Some of the resin and plastic alternatives for pearls are highly lovely while having almost no value. When compared to natural or cultured pearls, these often have a substantially lower specific gravity. Determining whether a pearl or strand of pearls is natural or produced is typically an issue for gemologists.
A rounded clam shell bead is inserted between the oyster’s shell and mantle to create a cultivated pearl. Previously, these beads were produced in Muscatine, Iowa, where a sizable pearl button industry previously thrived. The industry of pearl cultivation was developed in Japan using Pinctada martensii oysters as hosts. Oysters that are roughly three years old are given the bead. In one to two years, the oysters are harvested, and the pearls are taken out. At a pace of between 0.1 and 0.2 mm per year, the oyster secretes calcium carbonate surrounding the bead. Although the practice of pearl farming originated in Japan, it has since expanded to portions of Australia and American businesses are now engaged in fresh water pearl cultivation.
Only an X-ray can definitively distinguish a natural pearl from a produced pearl. Such separations cannot be made by rubbing the pearls across the teeth, candling them, or performing tests like specific gravity.
Pearl maintenance is crucial. Skin oils have the ability to quickly taint pearls. A knot will be placed between each pearl on a pearl string that has been properly strung to prevent friction. Excessive wear that reveals the non-gem nucleus can harm the produced pearl.
In This Article...
Do all birthstones contain minerals?
We collect rocks and minerals because we have a basic human need to own and wear things that we consider to be “holy” or extraordinary. This may help to explain the allure of birthstones and how compelling it can be to have our month of birth symbolized by a stunning natural gemstone. We may be the proud owners of our unique stone and enjoy admiring it for what it is. We hope you enjoy learning about the history, myths, and birthstones.
Difference between minerals and gems
Although all birthstones are made of minerals, why are certain of them valued as gems? Interestingly, the term “gem” doesn’t have a geological definition because a gem is a product of human creativity. Geologic processes in rocks in their natural environment cause minerals to develop. Gems are created when precious and semiprecious stones are extracted, shaped, and polished. A diamond becomes a jewel when it is put into metal and worn on the body.
The following criteria are important in determining a gem’s value: A mineral must possess the following qualities: scarcity, toughness, aesthetic appeal, size, and color.
Is the birthstone diamond a mineral?
Did you know that diamonds and pencil lead are both composed of the same substance?
Although it is hard to imagine, they are both carbon-based.
They differ because the carbon takes distinct crystal structures or shapes.
The hardest mineral is diamond, which rates a 10 on the Mohs scale of hardness.
Kimberlites and Lamproites are igneous rocks where diamonds are formed. These igneous rocks, known as peridotites, are mantle rocks that are often rich in the mineral olivine. Deep beneath the Earth’s surface, between 90 and 280 miles, peridotite rocks melt. As they ascend through fissures in the surrounding rock, they produce intrusions that resemble pipes. Some of the nearby rocks break off and merge with the flowing lava as it rushes through the fissures. The magma steadily cools over millions of years to form crystalline rock. These beautiful jewels known as diamonds can occasionally be found in these crystals. Kimberlite rock cores from a drilling and exploring project are shown in this picture. The rock cores are kept in these large crates before being examined. In order to perceive the rocks as one long string and determine precisely what is present below the surface of the earth, geologists store the cores in sequence as they remove them from the ground.
The largest diamond ever discovered weighs more than 7,000 carats, which is equivalent to the combined size of your two hands.
Diamonds are employed in a wide range of products, from jewelry to industrial cutting blades, due to their beauty and strength. A collection of cut and faceted diamonds of various sizes may be seen in the image on the upper left.
Is the birthstone sapphire a mineral?
The sapphire, the birthstone for September, is related to the ruby, the birthstone for July. Both are crystalline variations of the mineral corundum, which is composed of aluminum oxide. Ruby is the name for red corundum. And sapphires are the name for all other corundum crystals with gem-quality. On the Mohs scale, all corundum, including sapphire, has a hardness of 9. In terms of toughness, sapphire is now only second to diamond.
Sapphires typically come in blue gems. The exact colour varies depending on how much titanium and iron are contained inside the crystal structure, and they range from a very light blue to a deep indigo. The medium-deep cornflower blue is the blue that is most valuable. Fancy sapphires are sapphires that have additional natural colors and tints, such as colorless, gray, yellow, pale pink, orange, green, and violet. The varied colors of gemstones are caused by distinct types of impurities within the crystal. For instance, ferric iron gives yellow sapphires their color, whereas colorless stones are free of impurities.
In particular, New South Wales and Queensland in Australia are the largest sources of sapphires in the world. Australian sapphires are generally blue gemstones with a dark and inky appearance that are found in alluvial deposits of worn basalt. The Indian region of Kashmir was once well-known for producing the cornflower-blue stones. The Yogo Gulch Mine in Montana is a significant source of coal in the United States. Small stones for industrial usage are the main output.
Sapphire lore
The word sapphire has ancient language origins. It comes from the Latin word sapphirus, which means “blue,” the Greek word sappheiros, which refers to the island of Sappherine in the Arabian Sea, where sapphires were discovered in ancient Greece, and the Arabic word safir. Sapphire was known as the “Celestial Stone” in ancient Persia. It was Apollo’s diamond, the Greek god of prophecy. People who visited his shrine in Delphi to ask for his assistance wore sapphires. Sapphires were employed by the ancient Etruscans as early as the 7th century B.C.
The sapphire was said to stand for the purity of the soul in addition to being the birthstone for September. Priests wore it before and during the Middle Ages to guard against immoral thoughts and physical temptations. The kings of medieval Europe prized these stones for their use in rings and brooches because they thought it would protect them from harm and enmity. Warriors gave sapphire necklaces to their young wives in order to ensure their loyalty. The color of the stone was said to darken if worn by an adulterer, adulteress, or someone who was worthless.
Sapphires were long thought to offer serpent protection. People used to think that putting venomous spiders and reptiles in a jar with the stone would cause the animals to die right away. In the 13th century, the French believed that sapphire could change bad temper into good temper and ignorance into wisdom.
On Queen Victoria’s 1838 Imperial State Crown is one of the most renowned sapphires. It is kept in the Tower of London’s collection of British Crown Jewels. This gem is known as St. Edward’s Sapphire because it previously belonged to Edward the Confessor, who wore it on a ring during his coronation in 1042.
The birthstones for the other months of the year can be found here:
Granit is it a mineral?
Minerals called garnets can be found as single crystals, pebbles, or clumps of intergrown crystals. They are opaque, transparent to translucent minerals. The reddish hues of garnets are the ones that are most frequently found, although they can also be orange, yellow, green, purple, brown, blue, black, pink, and colorless. There are very few blue garnets. The crystals can occasionally have layers of contrasting lighter and darker colors.
Opal: a mineral or not?
Is there a member of your family who wears jewelry with opals in it? Opal is a “gemstone,” which is a mineral prized for its aesthetic appeal. The most popular gemstones to be found in jewelry are diamonds, rubies, emeralds, sapphires, jade, opals, and amethysts. Gems typically acquire their color from specific metals found in the material (for example purple amethyst is quartz containing tiny amounts of iron). Opals, on the other hand, are special because of the rainbow-like display they produce because of their inherent microstructure, which divides white light into all the colors of the spectrum.
Do amethysts count as minerals?
Amethyst is a clear, coarse-grained form of quartz, a silica mineral prized for its violet hue as a semiprecious gem. Although it has the same physical characteristics as quartz, it includes more iron oxide (Fe2O3) than any other variation of quartz, and researchers think that iron is what gives it its color. Other explanations link the color to the presence of hydrocarbons or manganese. Amethyst loses color when heated or turns yellow when heated.
Turquoise: a mineral or not?
the widely used gemstones turquoise, hydrated copper, and aluminum phosphate. It is a secondary mineral that is deposited by flowing streams, and it is most common in dry regions. It appears as blue to greenish, waxy veinlets in worn, volcanic, or sedimentary rocks that are high in alumina.
August is a mineral, right?
The clear yellowish-green magnesium/iron silicate gemstone peridot (pronounced pair-uh-dough) is the birthstone for people who were born in the month of August. Chrysolite, also known as olivene, is the mineral that peridot is a gem variant of, and its chemical formula is (Mg,Fe)2SiO4.
October is a mineral.
If you were fortunate enough to be born in the month of October, tourmaline and opal are both your birthstones. The Sinhalese word for multicolored stone, tura mali, is where the word tourmaline originates. Tourmaline is actually a set of minerals with a variety of chemical makeups and hues rather than a single mineral. The boron silicate mineral known as tourmaline is found in both igneous and metamorphic rocks.
Opal, which derives its name from the Greek word opallios, is the other birthstone. When you spin an opal, you can approximately translate this as “to notice a change in color.” Opals are created when water picks up silica dioxide and deposits it together with minute amounts of impurities into open cavities or voids. After that, the water evaporation leaves behind the silica dioxide. The majority of the world’s opal comes from Australia, where periodic rains frequently cause water to leach out silica and deposit it in ground cracks.
