You can't go wrong with giving an engagement ring with a solitaire brilliant (round diamond) of 1.00 carat. With its dazzling sparkle as a symbol of your love, this is the ultimate classic for a very good reason. Although there's nothing to prevent you going for a more personal touch like a trilogy ring with 3 diamonds, or a halo ring. And other cuts (especially the heart shape), or even a superbly coloured sapphire, ruby, or emerald as gemstone are also possibilities.