硝 is a Japanese kanji written with 12 strokes, listed here under the keyword “nitrate”. It is built from 石 (stone) and 肖 (resemblance). In Remembering the Kanji by James W. Heisig it is frame 120.
On KumiJi Glyph Explorer, open the parts search and type “stone” + “resemblance”. 硝 is among the results, together with every other character containing the same shapes.
Open 硝 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.