Crystal size will range from .25-.75" tall/wide & thickness will vary When choosing your size please note that each necklace comes with a 1.5" extender chain. Example: 16" + 1.5" ext = 17.5" Please double check your measurements with a fabric measuring tape or a piece of string/ cord with a ruler before ordering Note: Due to the nature of natural crystals, please expect some variation in size, shape, & color/opacity Jewelry info: Necklace closure is a spring ring clasp Metal is 14k Gold Filled or Sterling Silver. They both have a beautiful color, are non-tarnishing, & great for sensitive skin! Sterling Silver chain is known to slightly change color with wear. Please read my FAQ for tips on keeping it shining bright! Blue Lace Agate Crystal Necklace