Do you know the total weight in grams of the pair? Knowing that would certainly give you a benchmark on at least the value in gold. The two pearls which look to be around 4.5 +/- mm in diameter might be a total of 1 gram or less
The pearls are 7 mm - the markings on the ruler are 2mm apart. (My initial guess of 8mm in the post title was incorrect - I have measured them with a digital caliper tool since then and they are 7 mm each)
Oh yeah, I thought I was looking at 3/16 in. Being they're screw-back earrings it's hard to say how much in demand they'd be, but there's some gold there and that always has a pretty consistent value. The pearls I'm not so sure on what they'd be worth. Have you any idea of what you think they'd be worth?