Today I went to a pearls and diamonds appreciation class organized by the HK Tourist Board as part of their cultural kaleidoscope program. Since it was free and at a jewelry shop, I was skeptical at first that it was a guise for a sales promotion. But I’m happy to report that our instructor, Alex, didn’t try to sell us anything at all. In fact, the lesson was so informational and interesting that I really wanted to get a copy of the slides afterwards for personal reference. Unfortunately, the materials were copyrighted. So I’ll just have to share with you all what I remember.

The first topic we covered was pearls, and here are the highlights:

• Pearls are made when a piece of rock or sediment gets stuck inside a live oyster/mollusk. The oyster secretion, which happens to by full of calcium carbonate, then creates a layer around this rock called a nacre. And it is this coating of nacre that gives pearls all the pretty properties we love about it. I found this point especially interesting and wondered why I never thought to question how pearls are made and had just assumed that they came out of oysters.
• Cultured oysters are made when we put a man made sediment (usually made of oyster shells) into an oyster, manually stimulating the layering process. This usually takes 18-24 months. The best thing about it is that the pearl will come out in around the same size and shape as the one you put in. So the bigger and rounder the sediment you put in, the bigger and rounder the pearl will be. So I guess for pearls, size really does not matter too much, since you’re really just buying the coating.
• There are essentially two kinds of cultured pearls: freshwater pearls and seawater pearls
• Freshwater pearls: I don’t remember the full story, but the oysters in freshwater can produce more than one pearl (vs just one for seawater), and so are cheaper just by supply. In addition, somehow they cannot put perfectly rounded sediments inside these oysters, and can only put in tissues which change shape. Thus the pearls created in freshwater are typically not as nicely rounded and typically cost less. So when someone tries to sell you an “uniquely shaped” pearl, dont’ pay a premium for it!
• Seawater Pearls: The oysters here only produce one pearl each, so they’re rarer. They product is also typically perfectly round and can be quite large if need be. Though I think larger pearls are more difficult to cultivate successfully, and thus charge more. A good way to tell that they are seawater pearls, is to roll the strand across the table. Seawater pearls should roll very easily, while it would be a bit more difficult for freshwater pearls due to their irregular shapes
• Japanese pearls are typically small and no bigger than 10mm (mm is the size pearls are measured in)
• Black pearls have recently been quite popular due to their novelty. Only Tahiti and the cook islands make black pearls and the most expensive ones are the peacock colored ones, which is a combination of green and red tones. A good way to tell real black pearls from dyed ones (for necklaces at least), is to look at the hole where they poke the string through. There you can see the inside of the pearl, to tell if it’s black or white (which means they’re dyed)
• The natural color of pearls are usually quite pale and pastel, usually white, cream or pale pink. If the color is deep and sharp, then they’re dyed
• The most important factor to judge a pearl by is the sheen. The more reflective and sharp the reflection is, the better. The next factors include shape, size and color
• For necklaces, the pearl size usually differ by around 1 to 2mm from each other, with the bigger ones in the middle. Something about the proportions
• If you want to tell quality, look at the sides of a pearl necklace, because that’s where they usually put the pearls that are not up to par
• To differentiate fake pearls from real ones, a) rub the pearls against each other- real pearls have more texture and you’ll feel the friction b) if it’s a necklace, look at the point where they poke the holes. The edges for fake pearls are rougher c) Feel the texture. Fake pearls are much smoother than real ones
• Since pearls are essentially layers of calcium carbonate, they will not last you forever. But if you take good care of it, it’ll last longer. Here are some tips, a) put it on, 10 minutes after you’ve sprayed perfume. Perfume destroys the sheen b) wipe it down with a wet cloth after you wear it and let it air for 40 minutes. This cleans off the body chemicals that might wear down the pearls c) put it back into a soft bag to protect it

Phew~ that was long. And this is just what I remember! I’m pretty sure I missed out some of the other factors that are used to judge pearls. I should’ve taken notes! Stay tune for later this week for a girl’s best friend!