The Ancient Egyptians imported cobalt, mined in central Africa, to provide that deep, lustrous blue to ceramics, and it has been in great demand ever since - there will be some in the lithium-ion battery in your mobile phone, and electric car.
But this image - generated by digital microscope - is a new, different and stunningly beautiful image is cobalt in colour, but agate in mineral terms.
Still, it's rich, banded pattern certainly makes for a gorgeous image - and amazing that agate can reproduce the colour of cobalt, yet is a completely different mineral.
It works really dramatically well on silk on this long and thin format. We've already sold out of the larger square size!