15.47 is 80.11% of 19.31 (I just used a calculator) - this does not mean that this is 80% pure gold.
For that to be true the other matter in the gold nugget would have to be weightless.
As I said in a previous answer, if you dangle a lump of lead in water and use this method to calculate the density, you will get a density of 11.34. That is 58% of 19.31. This clearly does not mean that your lump of lead is 58% pure gold.
As I also said before, you have to know what is in your lump of gold (besides the gold) to ascertain how pure it is using the density alone.
For that to be true the other matter in the gold nugget would have to be weightless.
As I said in a previous answer, if you dangle a lump of lead in water and use this method to calculate the density, you will get a density of 11.34. That is 58% of 19.31. This clearly does not mean that your lump of lead is 58% pure gold.
As I also said before, you have to know what is in your lump of gold (besides the gold) to ascertain how pure it is using the density alone.
