Here's why:
* Proper nouns are specific names for people, places, or things. They are always capitalized. Examples:
* People: John, Marie Curie
* Places: Paris, Mount Everest
* Things: iPhone, Taj Mahal
* Common nouns are general names for people, places, or things. They are not capitalized unless they begin a sentence.
"Gold" and "spices" are common nouns because they are general terms for these substances.
Examples:
* Gold is a precious metal. (common noun)
* The Bank of England has large reserves of gold. (proper noun - Bank of England)
* Spices are used to add flavor to food. (common noun)
* Cinnamon is a popular spice. (proper noun - Cinnamon)