Pearls

Other pearl types:

Natural pearls - those created entirely by Mother Nature without any interference from humans. When a foreign object (irritant) gets into its shell, an oyster will respond by secreting calcium carbonate in layers around the intruder. Naturally occurring pearls are extremely rare because of the amount of years it takes for one oyster to naturally produce one pearl (anywhere from two and a half to eight years!) Pearls as a whole are considered one of the three biogenic gemstones (the other two are Amber and Ammolite)

Cultured pearls - created using the same way that natural pearls are, but in this case the foreign object(s) placed inside the oyster was done by man. Raised in a controlled environment, this type of pearl makes up the majority on the market today.

Saltwater pearls - grown in saltwater oysters. One pearl is grown in each oyster every two and a half years. Far more expensive than the freshwater variety. Some examples of saltwater pearls would be South Asian pearls, the very rare (and expensive!!) Australian pearls and the mystical Tahitian pearls.

Freshwater pearls - grown in freshwater mussels. Freshwater pearls are much smaller and less expensive to harvest than saltwater pearls. One mussel can yield upwards of twenty or more pearls in each harvest. The turnaround time for freshwater pearls is much shorter as well, with only one and a half to two years to grow each "crop" of pearls.

Keshi pearls - many different types of marine mollusks and freshwater mussels can produce these types of pearls. Small in size, these pearls are formed when an object that is planted into the mollusk is rejected, thus resulting in a "pearl" that is completely composed of nacre. Keshi pearls will have more luster than other pearls, and have a very organic shape.