What does, 925 and what looks like two circles side by side then a cz, mean on the inside of my ring? It's a silver looking ring with one big green jewel in the center and three small diamond looking jewels on each side of it.

This explanation might help --

2. Check the Setting - Real diamonds are normally set in yellow gold, white gold or platinum settings. Check the stamps inside the setting. If you see: 10K, 14K, 18K, 585, 750, 900, 950, PT, or Plat, the setting is gold or platinum, that is a good indicator that the stone set in it may be a diamond. However, if you see the letters GF, RGP, or GP, these indicate the setting is gold plated or gold filled. If you see: sterling, 925, 9.25 or .925, the setting is sterling silver. If the setting is not gold or platinum, the stone is most likely not a diamond. However, several popular jewelry designers, such as David Yurman, Judith Jack, John Hardy and others are setting semi-precious stones and diamonds in sterling silver and/or gold settings so while this is an indicator, the stamp in the setting is not a definitive way to determine if the stones in the setting are or are not real diamonds. Likewise, if you see a stamp that says C.Z., this indicates the center stone is a cubic zirconia (regardless of what metal the setting is), although not all settings with cubic zirconias are marked that way.

Diamond Earrings Best value Diamond Earrings Diamond Studs from Diamond Doctor (http://www.diamonddoctor.com/cms/12_ways_to_determine_if_a_diamond_is_real__part_1_ of_2_.asp)