If you touch the green stones and they are cold, and stay cold when your fingers are holding them, they are stone. Stone doesn't conduct heat like glass and plastic do. If they are stone vs glass or plastic, then they are nephrite jade. Hope this helps.
From my over 30 years as a jewelry designer, I suspect that it will say 10k. They may or may not be diamonds. If you have more jewelry to get rid of, I highly recommend buying a loupe. You can buy one from Firemountain Gems for cheap and it might save you from giving away something that is worth a lot! If you have questions and need quick help, email me at holli@hollidaysmith.com I will help all i can. :o)