They are green terrazzo tiles. Each green tile has a lot of big white flakes and tiny black flakes. All those fragments create this terrazzo.
Edges of each tile is a bit weary and the surface is rather shiny.
This is a seamless and tileable PBR CG texture for 3D artists.
Each package usually includes a Base Color Map / Diffuse Map, Normal Map, Roughness Map, Displacement Map, Metallic Map (Metals Only) and Ambient Occlusion Map.
It is FREE for personal and commercial use!
It can be downloaded at
https://www.texturecan.com/details/86/