Black pearl necklaces were made with names that are classified in accordance to the lengths of the necklaces. A choker length is the one that is placed on the foundation of the neck of the wearer, and a princess length is even more down to just under the collarbone. A longer length that is able to drop down to the breastbone is called an opera. This length may range as long as 900mm. A length even longer than this would fall into the name classification of rope and it can be as long as 120mm or more in length.

Rates of black pearl necklaces rely on the size and color of the pearls. Fundamentally called black because of its dark colors, they generally can be found in various dark colors of gray, green, blue, green, brown, red, and purple. Those that are really black are quite rare. Deep purple and dark green are frequently believed as rare colors. The dimensions normally vary from 8mm to 14 mm in the diameter. When buying one, pay attention to defects and also the smoothness of the surface. Luster is more important a quality than color and a level of AAA may guarantee the highest luster. A lower and less costly grade would be AA, but the luster is lower.

Black pearl necklaces are generally known as Tahitian black pearl necklaces due to the fact that the majority of black pearls come from the area of French Polynesia, a group of islands in the South Pacific. Among these islands, Tahiti functions as the trade center for the black pearl industry there. Other countries providing black pearls, on a smaller scale are the Cook Islands, Fiji, Japan and Philippines. These pearls are taken from the black-lipped oyster and are produced from pearl cultivation, a method that usually needs at least two years from the time of pearl induction to the time it is harvested.