Kezhart, these are ceramic mosaics from here-
If budget allows, you can get nicer ones in marble here - https://designermarble.com.au/collections/nero-marquina
(the 50mm size)
Alternatively, we also have the goods if you are unable to find what you need from those other sources.
Hope that helps!
Kitchen splash back
Fixed shower screens, does too much water spash out or not?
Please help my back yard, where can I put a deck?
Where to get purple floor tiles