What Are Pearls Made of?A pearl is formed when an irritant becomes trapped in it. The shellfish coats it with layers of aragonite and conchiolin ( "KON-kee-uh-lin") - the same substances the animal uses to build its shell. This composite material is called nacre or mother-of -pearl.
Pearl luster is formed by these overlapping platelets of aragonite and film of conchiolin reflecting light in a unique way. This light interference results in iridescent colors ("orient" in our GIA certificates as "pearl overtone") on the pearl surface.
One of the largest fine pearls - the Hope pearl - is 5 cm long, drop-shaped pearl weighing 454 ct (90.8 grams). It is found in the South Kensington Museum in London.
What kind of pearls are there?Pearls are usually described from an origin point of view - freshwater or seawater - and also from a natural vs. man-made description.
Natural pearls include those that occur naturally in nature + those that are farmed, the distinguishing characteristic of these natural pearls is its purity of at least 99.9% naturally occurring nacre, the rest being the original irritant or tiny seed used to simulate the growth of the pearl.
In the case of freshwater pearls, mollusks do not even need a seed to grow! The pearl once they "remember" how to make a pearl. As seen in our GIA certificates, our pearls are non-bead cultured pearls, meaning that they are 100% nacre.
For man-made artificial pearls, there are a variety of types, from plastic, or artificial mother-of-pearl made from a fish-scale based spray, or pearl-shell pearls. The latter are the most deceptive, and comprises of a huge plastic core that is wrapped by a few thin layers of nacre. How are pearls graded for quality?Just as diamonds are graded by the 4 Cs, pearls are graded in 7 ways - Size, Shape, Surface, Body Color, Overtone, Luster, and Matching.
What is Pearl Surface and why does it matter for pearls?Surface indicates the quality of the pearl in terms of visible scratches, watermarks, spots, whirls, and other blemishes. These blemishes occur naturally as the pearls are formed in a natural environment.
GIA's ranks pearl surface accordingly - Clean, Lightly Spotted, Moderately Spotted, Heavily Spotted. Pearl prices are affected by surface.
What is Pearl Overtone and why does it matter for pearls?Pearl nacre reflects light in a unique way, and this reflection results in a color overtone that increases the beauty of a pearl. This overtone can be in different colors of green, pink, and even multi-hued. GIA grades the latter as having an "orient" overtone.
The overtone color is different from the base body color of the pearl and can be seen in quality pearls under a bright lighting condition. For example, our premium white pearls are graded by GIA as having a white bodycolor with a pink overtone.
Pearl Authenticity
(1) The Teeth Test - Lightly rub or bite the pearl on teeth, it should feel gritty or sandy. Pearl shell pearls will pass this test unfortunately since the test is not deep enough to expose the plastic core.
(2) The Weight Test - Pearl shell or fake pearls may feel lighter when compared to normal pearls
Pearl Care
Like other jewellery, pearls require a certain degree of care.
Pearls in contact with skin - e.g. necklaces, pendants - should be cleaned with a soft, damp cloth as skin is slightly acidic. All pearls should also be stored separately from harder jewellery like gems and metals, ideally in a soft chamois container.
Contact with perfumes and other chemicals will also require cleaning to prevent tarnishing. To maintain pearl lustre, use some olive oil on your cloth.
Do not subject your pearls to : - Steam or ultrasonic cleaning - Scouring, brushing, or other rough materials for cleaning
Do remove your pearls during bathing or swimming.
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