The most common and most likely answer to this crossword clue is the 10 letter word GOLDSMITHS
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result GOLDSMITHS
Buddy explains!
The straight part
We know that "College/people dealing with precious material" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case college/people dealing with precious material = goldsmiths.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 GOLDSMITHS mean?
GOLDSMITHS noun- A person who makes, repairs or sells things out of gold, especially jewelry.
- A banker (because the goldsmiths of London used to receive money on deposit, being equipped to keep it safely).