Nose Stud. Green Titanium Gem Nose Stud (Nose Screw). 1mm Gauge. Available in a choice of gem colours. Curved comfort shape titanium nose stud set with sparkling gem. Made from surgical grade, green anodised Titanium, suitable for people with metal allergies. For use in the Nostril Piercing. For help with sizing please read our Sizing Guide. High quality Nose Stud.