Opal

An opal does not have a colour. It has an angle; turn it and the fire in it moves, which is why the stone was cut into inlay rather than beads, set flat where it could be looked at rather than worn end-on.

The fragrance is built to do the same thing. Aldehydes and white pepper open it almost colourless; silver iris and heliotrope give it a powdery centre that reads differently on different skin; white amber, mineral musk, and ambrette close it. Two people wearing Opal rarely smell as though they are wearing the same thing.