Lost weight when melting again???

Hi

I made a 9ct gold cast ring from scrap 9ct gold, I melted my filings and scrap I had left over after finishing the ring, and it weighed 21.01g. I then noticed I had some good left in the borax in my scorifier, so I melted the 21.01g back into it to pick up the rest of the gold.

I then weighed it again and it was 20.48g. what I assume is that some alloy metals in the 9ct were oxidised and were removed by borax?

If my assumption is correct, would that mean that I now have a slightly higher carat bullion?

Thanks

In theory yes, you've lost some copper as oxide. Your pickle will go more blue. In practice it doesn't make much difference, except that the colour of the metal will become a little more yellow.
If you make a pendant though, It's really hard to buy in a chain to match. Dennis.