Cabochon cut :
Means a polished dome shaped gemstone stone, without facet.
Carat :
The carat (ct) is a unit of mass equal to 2 g. Carat is used for measuring the weight of gemstones.
Amethyst :
Amethyst is a popular form of quartz that ranges from a bright to dark or dull purple color. Heated the color of the amethyst changes to yellow and is then called citrine.