Identifying gold dust, powder, leaf

I came across what I believe is some form of gold powder possibly used around 60 years ago with a pump sprayer for gold leafing. Its very fine and sticks to everything. Its been sitting in a shoe box in a musty basement for at least 60 years and shows no signs of tarnish and is bright. I acid tested it. The 22k and 14k acid turned it green and fizzed it out but the 10k acid turned it into a gold glob. I brought a small amount to one of those WE BUY GOLD places at the mall and the gentleman got excited when I told him how much I actually had and called a buddy and told him to go to home depot and buy some equipment to melt what I brought in. I got weirded out when he got got all shady talking about his cut and what not so I left.
Im wondering if it could be 10k gold leaf. I took photos but for some reason cant upload them.

Trying to find out how to perform a more in depth test or possibly where to send it for examination. I probably have enough of the powder to justify the costs of an analysis before searching for a buyer.

Thanks!