The Starlight Collection features a twinkling fusion of trillion-cut Ammolite and 925 Sterling Silver, inspired by the diffusing light of stars. A or AA grade Ammolite 18mm x 17.9mm trillion Ammolite pendant 925 Sterling Silver Accented with 2.0mm White Topaz Pendant Dimensions: 20.2mm x 19.8mm Chain Length: 16-18 Inch Adjustable Lobster Clasp with Ammonite Accent Like all gemstones, Ammolite should be treated with care and attention. -Avoid exposure to direct heat. -Do not over-expose to water. -Avoid hard impact to the stone -Do not clean in ultrasonic cleaners -Use a soft, none-abrasive cloth to clean your Ammolite jewellery.