Five Chinese characters “月”(moon) is a semi-circle with a dot in it. The moon has phases, so it explains why there is a semi-circle. The dot indicates that the moon glows. “雨” looks much like rains. The two lines on the top stand for the sky. “天” is a man with a square above his head. It means the space on the top. The original meaning of “厂” is actually the “cliff” as what it resembles. Then gradually it combined with another character "厰”", which represents an open and spacious building. "石"="厂"+"口", it stands for a square thing underneath the cliff. Yes, that's stone.