Decoding Jewelry Hallmarks: What Does a 'D' and '412/417' Mean?

Question
I have a sterling silver ring it marks 925 meaning its sterling silver but also marks a uppercase cursive D, what can the D stand for? I believe the stones are cubic zerconias* but doesn't mark a CZ.

Also I have a potentially gold ring that does not mark any amount of karats instead a 412 or 417 its not too clear; what do these numbers indicate; and does it have any value?

Answer
HI VALERIE,

THE CURSIVE 'D' CAN STAND FOR MANY THINGS. IN THIS CASE IT PROBABLY THE HALLMARK OF THE MFG. CO. OR A DESIGN DESIGNATION. THERE ARE MANY USES OF HALLMARKS.

IF YOUR RING DOES NOT TARNISH THEN IT COULD BE GOLD IN THE 10-12 KARAT RANGE BY THE NUMBERS ON THE RING. HOWEVER YOU WOULD NEED TO GET IT TESTED TO BE SURE. GOLD IS OVER $1000 PER OUNCE RIGHT NOW SO IT COULD BE VALUABLE DEPENDING ON IF IT IS GOLD AND WHAT IT WEIGHS. GOOD LUCK.

PETER