The most common and most likely answer to this crossword clue is the 4 plus 3 letter word IRON ORE
I've seen this crossword clue in The Guardian
I
R
O
N
O
R
E
More clues leading to the result IRON ORE
- Working men in rage smelt this
- A metal may be extracted from it – there’s iridium and gold in one
- Mineral Renoir mixed with ochre initially
- Haematite obtained from robust seaweed
- Anger hogs addicted to golden mineral
- Pressecho with gold ingot mineral.
- Property of mine in India or Reno, possibly
- Press old engineers to show where metal comes from
Buddy explains!
The straight part
We know that "smelt this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case smelt this = iron ore.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.