Gold
noun, suffix
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji you would normally think it uses the kun'yomi reading. Not this word, though. It still uses the on'yomi reading, which you learned with the kanji. Don't confuse this one with お金, though. That one uses kun'yomi which you know because it has a hiragana attached.
金のネックレスをプレゼントしました。
I gave her a gold necklace.
これは本当の金ですか？
Is this real gold?
日本には金でできたトイレがあるそうだ。
Apparently, there are toilets made of gold in Japan.