Well, since they weren’t in North America, he’d have no reference to make a Gila Monster. :D:D
As hinted at above, some experts have posed the possibility that the golden calf is a dig at the Hindus to whom the cow is a sacred-- but not divine-- icon. It wouldn’t be the first time religious zealots misrepresented another religion.
I am going to WAG on this and say that gold was not as scarce then, and since it was not as scarce, no one thought to hoard it, or otherwise restict the wearing of it.
Anyway, What I learned from my class in Old Testament is a little rusty, but I will second (or third?) the notion that Bulls and Bull Symbology was big for one of the rival religions. Our Professor (A Reverend) would always say that this religion was exactly what it appeared to be, ‘a bunch of bull’.
Yeah, when I took Biblical Hebrew I noticed that the word מקנה miqneh, which the KJV translated as “cattle,” meant sheep and goats as well as cows. Originally, the English word cattle meant ‘property’, not specifically cows. Likewise, the Hebrew word miqneh is derived from a verb meaning to acquire or possess. So etymologically it must have seemed like a good match, but in fact it’s misleading.
Cf the legal term chattel, an item of personal (as opposed to real-estate) property, derived from the same root as “cattle.”
There may well have been bull cults among neighbors of the Jews, giving rise to this particular image. The point for the Yahwists was that it was idol worship, forbidden by their code.
I recall a sardonic comment from a discussion elsewhere (which gave nothing of any help here): “Because a golden giraffe would have been topheavy to move around!” 
The Israelites went on a looting spree just after (or before - it’s mentioned twice) the final plague.
Exodus 12:35 And the children of Israel did according to the word of Moses; and they borrowed of the Egyptians jewels of silver, and jewels of gold, and raiment:
12:36 And the LORD gave the people favour in the sight of the Egyptians, so that they lent unto them such things as they required. And they spoiled the Egyptians.
I don’t think that would be the case. Forget about diamonds: It’s gold that’s really forever. If you break it up into little pieces, you can just melt those pieces down and forge them back into something big. And gold is essentially immune to chemical degradation: You have to really work hard at it to get it to react with anything else, and even if you do, it’s easy to get it back. So all the gold that ever has been around in the world still is around in the world, and the amount is constantly increasing.
I think a better explanation is to note that the Old Testament doesn’t actually say how big the golden calf was. It’s pointless to question “How did they get that much gold?”, when we don’t know how much “that much” was.
Um, what about per capita?
—Auntie Miriam, I want a lolly! I want it NOW!!!
—Of course, Amenhotep, in fact have two lollies just for being so cute, wouldums like anything else?