My Theresa studs are a classic stud earring with a rub over setting for a contemporary look. I set them with peridots, amethyst, citrines and garnets and with rarer stones when I find them on my travels.

Taken from the Greek word "amethystos", meaning sober; amethyst quartz has illustrious calming properties, protecting wearers with a sense of tranquillity and soberness. Famed for its regal deep purple colour, February's birthstone is said to enhance your focus and open your mind to critical thinking and clarity, and to also protect from inebriation. It is often worn by bishops set in a ring. Most are sourced from alluvial deposits in Brazil, Madagascar, Zambia and Uruguay, and Cassandra likes to juxtapose their splendour with rubies and aquamarine, or even green African garnets.