Sometimes the opal and ironstone combine in a way that looks like an object, a landscape, or a lifeform. This half of a Yowah nut looks like a penguin. Picture stones like this are collectible and most miners have one or two sitting on the shelf in their mining hut. This one is the size of my palm and has another half nut that matches it. There is no fire showing in the opal. So the opal that makes up the figure is called “potch” or “common opal”. This piece is still in the rough and has not been polished. I sawed two thousand Yowah nuts (yes, I counted them) and found only two picture stones.