arsenic
礵 centers on arsenic, a chemical element. The meaning is specific and technical, with no broader conceptual cluster.
礵 is a modern Japanese created character (kokuji) combining 石 (stone) with 霜 (frost), likely chosen to represent the element arsenic, possibly due to its metallic, stone-like nature and frosty appearance.
The stone radical 石 suggests a mineral or element, and the frost component 霜 hints at a cold, crystalline substance. Together, 礵 is the stone-like, frosty element arsenic.
For ソウ, imagine a frosty stone of arsenic being stored in a cold, snowy place: snow -> ソウ, tying the reading to the frost component 霜.