This is a paid asset, but now you can download 3D Coins pack (PBR) Free.
Detail this asset from Unity Store: Original Link
3D Coins pack (PBR) v1.0
“If possible, please buy the package to support the developer”
Pack includes 3 detailed coins with PBR materials. Penny, nickel, and dime. Objects are scaled to real-world values.
All textures are 2048×2048. Albedo, metallic, normal, and occlusion included.
570 verts, 560 tris
Demo scene from preview video included.