煉 - refine metals, kneading over fire

brick

chamotte brick

red brick

purgatory

firebrick

art of making elixirs (e.g. in Chinese trad. medicine); alchemy

boiled pine pitch and oil (traditionally used as a glue in archery, etc.)

wooden block

paving brick

elixir of life (prepared from cinnabar in ancient China)

ornamental tile; facing bricks