What a nice gift for your granddaughter!
That is a graduated strand of akoya pearls, sometimes called a "
momme" or "3.5
momme" strand (
momme being a unit of weight.)
These necklaces were commonly bought during the WWII / Korean War era by military men working in the Far East, who then gave them to their sweethearts. The fact that they were graduated helped make them affordable.
What is the clasp metal-- is it white gold? I think I see a little diamond there. It's a cute clasp!
It would be a good idea to restring the necklace before giving it to your granddaughter, so that she could wear it right away if she likes. Silk thread absorbs skin oils, lotions, and environmental pollutants and becomes weak and grimy. Weak silk can break. Silk also stretches, leaving gaps between the pearls, which you can see has happened there in the front center. You can take it to a jeweler to restring (this can be pricey) or do it yourself; I have a tutorial posted as a sticky on the Lowly Beaders Forum. Many of us restring our own pearls. It isn't hard.
People often ask about the value of inherited pearls.
I think the main value of inherited pearls is their sentimental value. You can't put a price on that!
Then there is
replacement value, for insurance purposes. Normally I'd say you could just look online to see what retailers are selling such a necklace for, but graduated strands are not the current style. In any case, I don't think it needs to be insured; it is not that valuable.
Some folks ask about value because they want to sell their inherited pearls. Now we're talking about
resale value, which is lower.
Unfortunately unbranded, pre-owned pearls simply do not hold their value. If the clasp is gold that would make the necklace more valuable, gold being so expensive now. Although you aren't planning to sell the necklace, you can get an idea of what it might sell for by going on eBay and doing a search for SOLD necklaces similar to yours.
One final thought: it might be a good idea to ask your granddaughter if she wants the pearls before spending money to restring them. Not everyone loves pearls, and even among those who do, not everyone likes petite graduated strands. Also, while they are sentimental to you, your granddaughter may not feel the same way. Young people often feel differently about the utility of jewelry in their lives. In my mid-20's I sold gold jewelry I inherited to buy camera lenses prior to moving overseas!