It depends entirely on what you have written in your paragraph. As we don't know what is in the paragraph nobody can help you.
Yes, the compound word 'rock collection' is the noun in the sentence. The noun 'rock collection' is a word for a thing.
we found this tawny color rock and took it home
verb
Soil can be carried away from it's parent rock by wind, water, ice or gravity.
The rock band was banned for shouting obscenities at the concert.
Shadows on the Rock was created in 1931.
Metamophic rock came from the volcano and it's part of rocks and minerals.
The nouns in the sentence are frogs, place, and place.
Gordor is the boss of the go rock quarts.
He was surefooted as he hopped from rock to rock.
In this sentence, "rock" is a noun.
The rock rocked the rock show like a rock star! This is one of many examples for sentence usage.
Yes, the compound word 'rock collection' is the noun in the sentence. The noun 'rock collection' is a word for a thing.
We tried to persuade the mayor to change his mind, but he was unyielding. The coal miners unexpectedly encountered an unyielding wall of rock.
Tap it with your stylus.
Crocodile rock - Made by Elton John
Matthew Charles Sanders, better known as M. Shadows, is the lead singer for the hard rock band, Avenged Sevenfold. He was born July 31st, 1981.