abstract appearance backdrop background close-up color colour Dirt drops feel garden garden pebbles gray grey pebble patch pebbles river rocks rocks rounded shiny smooth smoothed streaks surface surfaces textures varied veins rain rain drops 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