This question seems to crop up occasionally, you might want to take a look at the answers from /u/poob1x in this thread https://www.reddit.com/r/AskHistorians/comments/a0ev0h/why_gold/
/u/deadletter discuss its properties here in context of economics and its function as an "Indexing role" to contrast with the day to uses of other goods https://www.reddit.com/r/AskHistorians/comments/72afpu/how_did_gold_and_silver_first_become_precious/
/u/sabremesh gives the most detailed answer here alongside a few other commentators https://www.reddit.com/r/AskHistorians/comments/72afpu/how_did_gold_and_silver_first_become_precious/
You can also check the FAQ https://www.reddit.com/r/AskHistorians/wiki/economics#wiki_why_was_gold_always_considered_so_valuable.3F
Hi, friends,
AskHistorians is a subreddit where people with questions about history can get answers from those with expert-level knowledge in the topic. We ask that answers be in-depth, comprehensive, and supported by current scholarship. This does not include speculation based on economic theory or that podcast you heard that one time.
Re: this particular question, I'd like to point out:
The question is not "why has gold been used as currency"
Gold's use as currency is not because gold is inherently, scientifically the only or the best option: cowrie shells and tea bricks, for example, have been systematically and long-term used as stable currency.
The physical properties of gold have likewise been irrelevant in places that have used a 'gold standard,' as it were--in late medieval Europe, nearly all day-to-day transactions were in silver; gold was often transferred as credits/paper IOUs because people didn't actually have it.
Please don't clutter the thread complaining about the removed comments. It's not fair to OP, and it only makes things more frustrating for people who click on the thread expecting to see a large number of comments.
If you'd rather read AskHistorians in a way that all questions have answers, follow us on Twitter @AskHistorians!
Thanks!