Shiny granite close-up is regularly — this? (7)
I believe the answer is:
igneous
'shiny' is the definition.
Although both the answer and definition are adjectives, I cannot see how they can define each other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for igneous that I've seen before include "Formed of solidified magma" , "(Rock) set from lava" , "Produced by the action of intense heat" , "Of fire, like rocks formed from molten material" , "Type of rock with molten origin" .)