A synthetic form of corundum, given the trade name ‘honeycomb ruby’.
This material is brightly fluorescent, a hot pink – much like true ruby. This is lab grown, and is chemically a corundum – just not gem grade, so should not be considered ruby.
The bubbles are a great identifier to help you spot this material – no natural, earth mined corundum will have bubbles in.
As these are lab grown from aluminium oxide and impurities to produce colours, they may technically be a form of emery – but we’ll just stick with calling them a form of lab corundum, eh?
