I just posted this in another thread a couple of weeks ago, but it is pretty good.:
To describe faux pearls:
Faux pearls have fantastic luster on 100% of every part of all the surfaces- NO dull spots ever, anywhere.
They have perfect skins, never a blemish or dimple anywhere.
They are absolutely, perfectly round. Never anything but 8 way rollers on a good faux strand.
There is never a deviation in size in a matched for size strand. Nor is there a deviation in the rhythm of size increase in a graduated strand.
Not one faux pearl ever has a hint of a ring anywhere on it, not even around the drill hole.
Faux pearls never have differences in color from pearl to pearl, no matter how slight. If you take a photo, they will all photograph the same.
Faux pearls never have the slightest of color discolorations anywhere under the surface.
You can?t look into or through the surface layers of any part of any faux pearl, ever.
If you look at a string of pearls that exhibits all above traits, except the last one, they are either faux or they are worth more than most people can pay.
Under magnification, Faux pearls usually have a plastic or glass bead visible at the hole?s edge. Also under magnification, the edges of the hole may show slight separations from the bead or even chips missing.
The ultimate test for the usual faux pearl is the ?tooth test. Rub a pearl surface on the edge of a tooth. Faux will be smooth, ?real? nacre will be slightly gritty with tiny grits.
This above list does not apply 100% to a lot of shell pearls and high grad faux pearls made from compounds. Some of those even pass the tooth test.
Most faux pearls except brand name ones such as Majorca don?t have any iridescence. The iridescence on Majorcas, is equally distributed everywhere on the surface, from all angles.
In general, Majorcas cost way more than any other faux pearls, more than many cultured akoyas, for sure, if they have the clasp certificate and box.
If your grandma's pearls are not faux, checked to see if they are cultured with a bead inside by checking around the drill hole.
I doubt they are "real". Most grandmothers have been receiving cltured pearls since the 1930's, though many grandmother's believe they are Real Pearls, they atre actually cultured in Japan.
