Pareidolia means the illusory perception of meaningful or familiar images in random or amorphous objects: think of clouds that look like dragons, the man in the moon, faces emerging from patterned wallpapers. The most extraordinary of all these are picture and landscape agates and this one is certainly remarkable. I think of the person who cut the stone and how they would have seen a bird, just as we do. Most of the agate is clear and, as we always do with agates, it is thinned to 0.5 of a millimetre. At this point the gold of the tail and the head crest emerged more clearly and the blackbird became a peacock. We have a sample sheet of all the different precious metal leaf colours and the one that worked best was palladium – quite a surprise. It is currently the most expensive precious metal and is used for catalytic converters to mitigate harmful emissions in cars.

18 carat yellow and white gold; silver; palladium; pearls; sea urchin spine ends; diamond beads.