This effect is very east to achieve without breaking the bank! Very Simple, buy a stock image or buy a small stone and take your own shot. Take the image to a sign company have them print out any size you like, have it laminated, or you could even cover with a clear sheet of plastic or glass, if you don’t want to hold with screws, you could just add trim around it. Backlighting can also be done if you have the sign company print it out translucent or at 80%, then stick on plastic.