A classic strand of Australian South Sea cultured pearls. Photo by Australian Pearl Center The answer is yes.Instead of waiting for nature to create this amazing gem by chance, trained technicians have a hand in creating it. So now you ask, how are pearls made anyway? Pearls are created inside the body of the Pearl Oyster. Just like you and I, an Oyster Pearl’s body tries to get rid of any foreign objects that gets inside its shell. Sometimes when the oyster cannot expel the foreign object, the oyster isolates it inside a membrane or pearl sack that secretes nacre. Nacre is the same smooth substance that lines its shell. The foreign object is slowly plated with translucent layers of calcium carbonate crystals (nacre), which make it smooth and tolerable to the oyster. Pearl oyster is a member of mollusk family, with over 130,000 living species, but only a few species can create the gem quality we value as pearl.
Persicae Roseae - Rosy Peach Cultured Saltwater Akoya Pearl and 14K Gold Necklace Set from MaryBlum's Shop on Etsy
Cultured pearls are created by humans inserting a foreign object between the shell of a Pearl oyster and its nacre-producing mantle. However, this process did not always create round pearls. It was not until late 19th century when Kokichi Mikimoto, the son of a noodle maker, discovered the secret to making cultured round pearls. The procedure is called nucleation, where a small mantle tissue from another oyster is used to form the pearl sack. To see the process watch the pearl nucleatings video. As you can imagine, this revolutionized the pearl industry. Pearl Farms and farmers were developed. Japan’s pearl industry expanded to other countries such as Burma, Australia and South Sea. South Sea pearls are produced mainly in Australia, the Philippines, Indonesia and Myanmar. Australia produces the biggest and most expensive pearls. The smaller Japanese pearls are still the most popular and affordable. 
A beautiful white Chinese fresh water button pearl set in 14KY gold from Omoridesigns's shop on Etsy
Everything we talked about so far relates to Salt Water Cultured Pearl. The other more popular and relatively less expensive kind is ‘Fresh Water’ Cultured pearl. Fresh water pearls are produced by freshwater mussels that live in ponds, lakes, and rivers. China has been producing them in the form of mabe since the 13th century. Mabes are formations, bumps, and half-domes that grow against the shell's interior surface.
Today, China is the world’s leader in producing fresh water pearls. Cultured fresh water pearls are of excellent quality, luster and shape including round. However, because they are solid nacre, they are more resistance to chipping, wear and degeneration.
Floral Keshi Pearl Earrings from Srdesignstudio's shop on Etsy
Keshi pearls are produced when the oyster spits out the implanted nucleus before the culturing process is formed. Keshi pearls are produced by both saltwater and freshwater pearl oysters and their shape varies widely. Keshi pearls have excellent luster and shimmering surface.
White Keshi Pearl and Blue Diamond Ring from Fairchild & Co
“Keshi Pearl Floating in an Oyster Dish” ring uses an American keshi pearl “floating” on 18k yellow gold with two American keshi pearls from Stephen WrightWright & Co.Indianapolis, IN
Natural Luster White Mabe Blister Pearl Pendants (1pc)from Emass's shop on Etsy
A mabe pearl is a hemispherical shaped pearl which is grown against the inside of the oyster's shell, rather than within its tissue. Cultured mabes are grown intentionally, by using a hemispheric nucleus, rather than a round one; and by implanting it against the oyster's shell, rather than within its tissue
Mabe Pearl and Abalone Necklace from ErinPettitDesigns's shop on Etsy
The only way to tell the difference between a cultured and a natural pearl is by x-ray which reveals the inner part of the pearl.
Sources:
The History of Pearls © by Fred Ward
Cultured pearl From Wikipedia, the free encyclopedia
Pearl-Guide.Com
"The Perfect Pearl" PBS Airdate: December 29, 1998
