If it is positive, then you may have a hepatitis B infection. This test may have to be repeated to confirm whether you have a chronic infection. 2. Hepatitis B surface Antibody (HBsAb or anti-HBs) - this tests for the surface antibody that your immune system makes to fight off the virus.
Rottenstone definition, a friable stone resulting from the decomposition of a siliceous limestone, used as a powder for polishing metals. See more. Dictionary.com
touchstone A criterion or test; a standard or measure. A touchstone is literally a smooth, black, siliceous stone used to test the purity of gold and silver alloys. By rubbing the alloy on the stone and analyzing the color of the streak on the stone, the gold or silver content can be determined.