I'm a smooth pale grey chalcedony, one of the many forms of agate. I'd quite like to be in a pendant one day.

I'm a topaz. My relatives come in a whole spectrum of colours, from browns, oranges and yellows to hot pinks. I'm one of the more unusual ones in that I am a lovely pale grey with barely a hint of yellow.

I'm an opal. In Shakespeare's time I was considered unlucky, a symbol of inconstancy, because of the way my colours change at different angles. Actually, though, I'm a friendly little gem who likes nothing better than to delight you with my subtly pretty colours.