The most common and most likely answer to this crossword clue is the 6 letter word PLACER
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More clues leading to the result PLACER
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The straight part
We know that "mineral deposit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mineral deposit = placer.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.
What does PLACER mean?
PLACER noun- One who places or arranges something.
- One who deals in stolen goods; a fence.
- (sheep) A lamb whose mother has died and which has transferred its attachment to an object, such as a bush or rock, in the locality.
- A place where the superficial detritus is washed for gold, etc.
- (by extension) Any place holding treasures.
- Alluvial; occurring in a deposit of sand or earth on a river-bed or bank, particularly with reference to precious metals such as gold or silver