Danny, I believe they're porcelain, but I'm sorry we just don't have a record of this. We mostly source our tiles from Perini in Richmond, but given stock is so transient and this was a few years ago now, you'd be best to take this photo into a showroom and ask them whether there is something similar available now rather than asking for a specific tile which is probably not even made any more. All the best.
Which tiles for kitchen walls & splashback?
Splashback? 3mm thick porcelain tile slabs
Kitchen done but which Splash-back?