Another thing to try (another time) would be to pour the gold about 1/2 - 3/4 of the way with the solid gold, let that firm up and then top up with thin mix of the gold mica
I did these earlier this year and needed different shades of gold and having the under layer helped.
I had a few other issues with these that made them unsatisfactory, but getting the result I wanted with the layering was a good learning experience.