硝石

1. Origins, structure, and basic meaning

• Structure: 硝石(しょうせき) means niter, the mineral potassium nitrate.
• Basic usage: It appears in descriptions of historical material use or the identity of a collected mineral.

2. Common pitfalls and similar expressions

• Similar written forms, different readings
  • 硝石, read しょうせき, is the mineral niter; 礎石, read そせき, means a foundation stone or a figurative foundation.