February - Amethyst.
March - Aquamarine, light blue.
April - Clear Crystal.
May - Emerald, dark green.
June - Light Amethyst, light purple.
July - Ruby, rich red.
August - Peridot, lime green.
September - Sapphire, royal blue.
October - White Opal, opaque.
November - Topaz - yellow / gold.
December - Turquoise
Each stud is made from sterling silver (925) and Swarovski elements crystal.
Each stud measures just over 5mm in diameter with a set 4mm crystal. The earrings are 1.3cm from the front of the crystal to the end of the post.