Blue Black Granite Flammed Setts are directly imported from China which are cut by Machine & Top is flammed . When dry the product is more of a Grey/Blue but when wet it gives you a black look as seen in the pictures. 
 
An ideal application would be for courtyards, driveways, paths and patios, when laid on an adequate sub-base and mortar bed. In the UK, this material is named as mid grey granite & blue black granite. These are  original G654 Chinese granite cobbles