I actually did some googling on the subject after posting this.
Turns out mining dogs are an underutilized resource.
Since gold itself is so inert with minimal scent, dogs were trained to sniff ore more for all types of metal.
I don't think I'd personally rule out dogs actually smelling gold tho'. They're noses are drastically more sensitive than humans and there is a demo on YouTube of a dog sniffing out river gold.

I've personally never tried scent search training but my little Crystal loves games.
Anyone want to discuss training strategies for your furry prospecting partner become more of a partner?

Kat

My lady has a standard poodle as her diabetic allert animal. Will punch her knee with the nose when blood sugars are too low or high, also alerts to anyone else in the same situation.  Picks up the keytones.  We were on a chapter outing last week and was kidding her about getting Ginger to find it for us...

Now to just get enough gold for her training to begin........

Update:
Apparently, gold smuggling is a problem in Japan.
They have custom trained dogs to help sniff out Gold smugglers!
Found this inexpensive little treasure on Amazon:

How to train your dog to find gold: training your dog to find precious metals https://www.amazon.com/dp/1453607137/ref=cm_sw_r_cp_apa_i_oMQgBb4MAD52S

The author now custom trains mineral dogs for a living. 🙄

Enjoy!
Kat (Mary)