Pearl

Pearl gallery pics

A pearl is a hard, shiny object produced in living tissue such as a crustacean mollusk or fossil conulariids. It is generally composed of calcium carbonate and mainly aragonite. Shell-secreting cells are found in a layer of the body tissue of the mollusk called the mantle. When a foreign particle enters the mantle, it forms concentric layers of pearls around the cells. .It can take many different shapes, but the ideal pearl is perfectly round and smooth. Colors vary according to the mollusk and its environment and range from black to white, cream, gray, blue, yellow, green, lavender. The most beautiful pearls are produced by freshwater and saltwater oysters.

The most valuable pearls are spherical or drop-shaped, with a deep luster and good color. Rose colored Indian pearls are very valuable (Bonewitz)

The most valuable pearls are those that occur naturally in nature and are very rare. These pearls are called natural pearls. Cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of what is currently sold.

Name: The English word pearl comes from the French perle, originally from the Latin perna, meaning leg, after the ham or mutton leg-shaped bivalve.

The scientific name of the pearl-bearing oyster family, Margaritiferidae, comes from the Old Persian word for pearl *margārītas

Mineral Group: Calcium carbonate and conchiolin (organic) combined with water

Environment: Formed by saltwater oysters, some fresh-water mussels and more rarely by other shellfish.

Pearl Physical Properties

The weak parts of the pearls are due to the refraction of light from the translucent layers. The thinner and more the layers in the pearl, the finer the shine. Also, cultured freshwater pearls can be dyed yellow, green, blue, brown, pink, purple or black. Most pearls have a metallic mirror-like good sheen.

Crystal habit	Amorphous
Color	White, Blue, Green, Yellow, Orange, Brown, Pink, Purple, Gray, Black, Multicolored
Streak
Luster	Pearly
Cleavage	None
Diaphaneity	Opaque
Mohs Hardness	2.5 – 4.5
Crystal System	Orthorhombic
Density	2.6 – 2.8
Fracture	Uneven

Optical Properties

Color / Pleochroism	Absent
RI values:	1.52 – 1.69
Birefringence	0.156

Pearl Occurrence

Previously, natural pearls were found in many parts of the world. Today’s natural pearls are mostly confined to the seas off Bahrain. Australia also has one of the world’s last remaining pearl diving ships. Australian pearl divers dive into south sea pearl oysters for use in the cultured south sea pearl industry. The hunting of pearl oysters is similar to the number of oysters collected during natural pearl days. Therefore, a significant number of natural pearls from wild oysters still exist in Australian Indian Ocean waters.

In jewelry

The value of pearls in jewelery is determined by the combination of luster, colour, size, lack of surface imperfections and symmetry appropriate to the type of pearl being studied. According to jewelers, the most important differentiator of pearl quality is brightness.

But all factors being equal, the bigger the pearl, the more valuable it is. Large, perfectly round pearls are rare and highly prized. Teardrop-shaped pearls are often used in necklaces.

Pearl Treatments And Enhancements

Today almost all Pearls are Cultured Pearls. It is dyed to give pearls an ancient color and to color their hue. The most common colors they are painted in are black and navy blue. Imitation Pearls are very easy and widely available. Natural Pearls are available for sale at affordable prices but lack the welcoming quality. They can also be easily distinguished with a microscope and can feel easily.

Pearl Uses Area

Pearls are among the most popular gemstones and have been used since ancient times. All colors and varieties of pearls are used as precious stones and are especially preferred as necklaces. Pearls are also commonly used as bracelets and can also be the center stone in rings, earrings and pendants. Necklaces are usually made of non-round Pearls like baroque shaped Pearls.

References

• Bonewitz, R. (2012). Rocks and minerals. 2nd ed. London: DK Publishing.
• Gemdat.org. 2021. Pearl gemstone information. [online] Available at: <https://www.gemdat.org/gem-42674.html> [Accessed 25 October 2021].
• Minerals.net. 2021. Coral: The gemstone coral information and pictures. [online] Available at: <https://www.minerals.net/gemstone/coral_gemstone.aspx> [Accessed 24 October 2021].
• Wikipedia contributors. (2021, October 21). Pearl. In Wikipedia, The Free Encyclopedia. Retrieved 19:00, October 25, 2021, from https://en.wikipedia.org/w/index.php?title=Pearl&oldid=1051080504