Dainty 925 Sterling Silver 18” Chain Necklace w/ Faux Peridot Glass Pendant

Dainty 925 Sterling Silver 18” Chain Necklace w/ Faux Peridot Glass Pendant. Rolo chain. Spring ring clasp. Small round pendant barely over 1/4 of an inch in diameter. Marked “925 RJ” on the back. I tested that center light green stone in the center with a Presidium gem tester. It’s glass. I’m assuming that the clear rhinestones surrounding it are probably also glass. A little research for the RJ suggests the pendant could be Avon; I believe they did do some sterling, but I don’t have any marks to support it. It’s possible that this chain isn’t the original chain, but it’s still sterling silver as is the metal on the pendant. I’ve tested both.