Engraved River Stones Size: 1.5"-2.5", 2"-3", 3.5"-5.5" River stones are the naturally and highly polished stones and which is hand-picked for color. They are perfect for personalized rocks and Koi ponds, these beautiful stones come in a variety of colors direct from Mother Nature such as black, white, brown, red, yellow, green and mix-colors. We can engrave the words, phrase and images which have in your minds on it.