The Asscher cut is a square step-cut diamond with deeply cropped corners that create an almost octagonal outline. Its concentric square facets draw the eye deep into the stone, producing a mesmerising windmill pattern. Invented in 1902 by the Asscher Brothers, it remains one of the most distinctive and collectible diamond shapes.

A halo setting surrounds the centre diamond with a border of smaller pavé diamonds, creating a frame of light that makes the centre stone appear 20–30% larger. Halo settings add vintage character and maximum sparkle, catching light from every angle.

Under £2,500, a 1ct lab-grown diamond engagement ring in platinum or 18K gold is well within reach — with budget left over for a more intricate setting style such as halo or side stone.