Screw Back Moissanite Studs, 0.1ct to 4ct in 925 Silver

The screw back is the feature that sets these apart. A standard butterfly back is held by friction, and over time it loosens, which is how single earrings get lost. A screw back threads onto the post and locks in place, so it stays put through sleep, sport and the occasional snag. It matters more as the stone gets bigger and heavier, because a larger stud puts more pull on the back, which is exactly where the screw back earns its place.

The stones are round cut, D colour, VVS1 clarity moissanite set in 925 sterling silver. D is the top of the colourless range and VVS1 means no visible inclusions, so the stone stays clean and bright. Moissanite measures 9.25 on the Mohs scale, with a refractive index of about 2.65 against diamond's 2.42, so it is both hard enough for daily wear and livelier than most stones at this price.

The range is wide, so use the millimetres. The 0.1ct at 3mm and 0.3ct at 4mm are discreet. The 1.5ct at 7.5mm and 2ct at 8mm are the confident everyday sizes. The 3ct at 9mm and 4ct at 10mm are bold statement studs, and they are the sizes where the screw back really justifies itself. Choose a silver, gold or rose gold finish. The larger sizes are best on a lobe with room to carry them.

• Stone: round cut moissanite, D colour, VVS1 clarity
• Sizes: 0.1ct 3mm, 0.3ct 4mm, 1.5ct 7.5mm, 2ct 8mm, 3ct 9mm, 4ct 10mm
• Metal: 925 sterling silver
• Finish: silver, gold or rose gold
• Fitting: screw back
• Wear: unisex stud, sold as a pair