Blackening Silver: Does It Cause Brittleness?

Question
I am using a silver chain that is very small (.9mm) and have used Jax blackener to make it as dark as possible. It seems to be brittle after blackening - it breaks easily. Does blackening silver make it more brittle?

Answer
Dear Kanina,
Jax blackener is mostly used to darken aluminum, it was made for that purpose.
Silver Black, which is mixture of hydrochloric acid and tellurium, is a product that has a similar affect as liver of sulfur in that it oxidizes metal.
However I don't see the reason for the chain to get brittle at all unless you kept it in the mixture for too long even though it should not cause such a problem.
Hope it helps.
Orlando