Your title says Keller but the card says
Heller.
I did a search of this forum to see if anyone had ever posted about this brand (Heller) and there are some posts. See these threads:
Hello all. I am new to this forum and are need of your opinions/assistance. My Grandmother left me a multistrand of cultured pearls, in a blue original box, with a certification that says Heller certified cultured pearls H350". She also left me a note to sell them? interesting... Anyway, I...
www.pearl-guide.com
I recently went to a local jeweler's estate sale. I purchased a single strand, graduated, cultured pearl necklace about 16- 18" long with a certificate and number of 'H 260' and an envelope with extra pearls. It seems in very good condition. I would like to know any information about the value...
www.pearl-guide.com
It may be that the primary value of these pearls is
sentimental. Per the card that came with them, they are apparently cultured akoya pearls.The clasp is only 10K gold; usually higher karat gold is used for higher quality pearls (but not always.) The pearls and the silk are extremely grimy. It is obvious that their previous owner loved and wore them a lot! But the grime makes it hard to see what they actually look like, and the nacre may also be a bit worn and dulled; you won't know until you clean them. We can give you instructions on cleaning them. They also absolutely need to be restrung before wearing. Old, dirty silk is very weak and could break, causing the loss of the necklace or of some pearls.
However, I get the impression that you are interested in their value for resale purposes. If so, be aware that pre-owned cultured pearls tend not to hold their value; the exception is if they are Mikimoto or if they are important historic pearls. If you are trying to estimate what you might get for them, check sold listings on eBay for two-strand graduated pearl necklaces. that will give you an idea of what someone might pay for them. But if the buyer has to restring them, the value will be much less. Restringing can cost $3.00 or more per inch, per strand. If the buyer has to shell that out, they will offer less for them. If you pay to have them restrung, you may only break even when selling-- if that!
If you want to wear them yourself, then first clean them, and restring them yourself! I wrote a tutorial on how to do it, posted on this forum (sticky on the Lowly Beaders Club forum. It's not hard! And it saves money.