It can be both. If it is capitalized, it is someone's name and thus a proper noun. If not capitalized, then it is the gem stone and is a common noun.
Proper noun
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Common
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Common
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
The noun 'Sapphire' (upper case S) is a proper noun, the name of a person.The noun 'sapphire' (lower case s) is a common noun, a general word for a bright blue precious stone; a general word for a shade of blue.A noun used to describe another noun is called an attributive noun.Examples:sister Sapphireauthor Sapphirecolor sapphireflame sapphire
Pencil proper or common noun
it's a common noun. a proper noun would be Spider-Man.
Proper noun or common noun
The noun cassette is a common noun.
a common noun?
The answer is proper noun. Examples of common noun and proper noun are: Proper noun: Mary Collins Common noun: monkey