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! Clear Quartz Crystal Necklace