I can’t tell if this Chinese coin is genuine or fake

I had been given this coin from my Auntie and she claims it’s a old Chinese coin. She had bought it 50 odd years ago while in China. Can anyone give information about this coin? Like what the characters mean, if it’s real or fake and whether its worth anything? I’ve also noticed that the coin has this moss like coverage over it. I’ve read online that it could be an indication that it is from many years ago. Any information on it would be helpful. Thanks

I have a website here with the exact same image. It is in mandarin but web browsers seem to translate it over to the language you need. Hope this helps! https://baike.baidu.com/item/%E5%90%8C%E6%B2%BB%E9%80%9A%E5%AE%9D/9665402

It's a modern amulet in the name of Tongzhi Boo chiowan, milled during the last quarter of the XXe century.

An evocation of this coin : 

N#19923

You are sure that is not a genuine coin due to the “elegant” calligraphy of “chiowan” on reverse.

By using anachronistic calligraphy, the manufacturer wanted not to  deceive the collector.

Here is a similar (not the same size) charm for fengshui purpose.

N#126466