The most common and most likely answer to this crossword clue is the 4 letter word MICA
I've seen this crossword clue in The Daily Telegraph
M
I
C
A
More clues leading to the result MICA
- Mineral doused in formic acid
- Rock-forming mineral, not for surfacing material
- Mineral that could be discharged by seismic activity
- Material in holy book not hard ultimately
- Utterance of prophet? It’s usually transparent
- Note about mineral
- Mineral found in outskirts of Minorca
- Insulating material in my car, I hear
- Account I am recollecting about shiny substance
- Insulator for first piece of audio equipment?
Buddy explains!
The straight part
We know that "It’s usually transparent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s usually transparent = mica.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 MICA mean?
MICA noun- Any of a group of hydrous aluminosilicate minerals characterized by highly perfect cleavage, so that they readily separate into very thin leaves, more or less elastic.