Prasiolite is the green variety of quartz. It's sometimes called "green amethyst", but this is a misnomer, as amethyst is the purple variety of quartz.
Prasiolite has a pale green colour; the bigger the stone, the more colour saturation.
This is a durable gemstone, and is ideal for all kinds of jewellery. We recommend cleaning this precious stone with a mild soapy solution and a soft brush (we use an electric toothbrush). Avoid storing in direct sunlight and, as with all of your jewellery, store this precious gemstone carefully to avoid knocks and abrasion.