What's the Difference? - Cultured Pearls Or Natural

What is the difference between Cultured and Natural Pearls? The difference is in the initial way the gem is provoked. Natural pearls have formed by accident, without humans being involved in the process. Cultured pearls have grown in an oyster or mussel after humans have inserted a tiny irritant to provoke the development of the pearl.

How Natural Pearls Form

The irritant that initiated the formation of a natural pearl may have been a parasite that penetrated the shell of the mollusc, disturbing the layer of mantle cells that produce the shiny interior of the shell. These dislodged mantle cells then multiply until they meet each other, forming a small pearl sac. Inside this sac the mantle cells secrete the nacre that would normally have formed into mother-of-pearl on the inside of the shell. But within the little sac that has formed, layer upon layer of nacre builds up and grows into a natural pearl.

How Cultured Pearls Form

Humans deliberately insert a tiny piece of mantle tissue into a mollusc to provoke the growth of a pearl sac, where a pearl will form. Freshwater pearls are formed this way. The rest of the process proceeds the same way that a natural pearl would form. Saltwater varieties of cultured pearls have a tiny bead made from the shell of another mollusc surgically inserted along with the mantle tissue to ensure the roundness of the pearl. The oyster will then proceed to coat the bead with layer upon layer of nacre until a pearl is built up over time.

Distinguishing Between Natural and Cultured Pearls

As both types of pearls are produced by the same animals with the same nacre, they can be hard to distinguish with the naked eye. Before the advent of tissue nucleation, the presence of a bead nucleus was the determining factor in distinguishing between the two. In a process similar to the old custom of candling eggs, pearls can be held over the beam of a flashlight to try to determine if they contain a round nucleus. Alternatively, the pearls can be analyzed under ultraviolet light that will show natural ones in varying intensities of yellowish or tan color as opposed to the blueish white color displayed by cultured ones. When purchasing what you believe to be a natural pearl, it's always advisable to ask the seller to provide certification of its being natural from a reliable gemology laboratory. There trained specialists use x-ray equipment to determine the type of pearl it is. Natural ones on average tend to be smaller in size than cultured ones. Necklaces are seldom of completely uniform color and perfectly matched shapes. But because of their rarity, newly found natural pearls are usually much more expensive than cultured ones.

Other Types of Natural Pearls

Not all pearls are formed in the way described above. Some are non-nacreous. Gem experts don't consider them true pearls, because they have no nacre, but they are beautiful and highly valued. Examples of these calcareous concretions are those produced by the Queen Conch and the Melo Melo Snail. Both produce gem quality pearls. Pink conch pearls and orange melo melo pearls have both been considered natural pearls until recent breakthroughs in the culturing of the conch pearls. Up till now almost all of those available for sale have developed as accidents of nature and fetch a high price. They seem to be more prone to fading than nacreous ones, so should be kept out of sunlight. The most highly valued have an intriguing flame structure, which gives the appearance of fine lines reminiscent of wet silk, or a cat's eyes. These pearls are very hard to find and are usually sold as a single pearl or pair rather than as pearl necklaces. The pink conch pearls tend to be very small in size.

Latest collections of Pearl Necklaces and Tahitian Pearls and Akoya Pearls on lagunapearl site.