Mineral discovered in a Scottish chimney (4)
I believe the answer is:
alum
'mineral' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'a scottish chimney' is the wordplay.
'scottish chimney' becomes 'lum' (Scottish term for a chimney).
'a'+'lum'='ALUM'
'discovered in' acts as a link.
Can you help me to learn more?
(Other definitions for alum that I've seen before include "Compound used in dyeing and to stop bleeding" , "White mineral salt used in medicine and in dyeing" , "Sulphate; maul (anag.)" , "Colourless compound used in dyeing and tanning" , "Compound used in tanning and dying" .)