abstract appearance backdrop background close-up color colour Dirt drops feel garden garden pebbles gray grey pebble patch pebbles rain rain drops river rocks rocks rounded smooth smoothed surface surfaces textures varied shiny streaks veins colored colors coloured colours decorative striations tactile variations variety veined garden-pebbles pebble-patch river-rocks shape shaped shapes small surfaced surfacing texture textured thick thin blades broken coral fragmentary fragments grass shells stones