Achieving Deep Black Oxidation on Sterling Silver: Tips & Troubleshooting

Question
Hello Peter,

Thanks in advance for your help.  I'm oxidizing sterling silver for the first time.  I used a Jax product with so so result and I'm now trying liver of sulfur.  The LOS is getting my pieces a nice gun metal grey but not black and there are a couple of pieces that I want completely black.  I read that adding ammonia to the los will help, I did that and it did help a bit but it's still no where near black.  The method I'm using is mixing the los with hot water in a bowl, next to that I've got a  simmering pot of water on the stove.  I'm heating up the pieces in the water, letting them rest in the los mix for 30 seconds, then dipping in the hot water again, repeat, rinse & dry.   Any suggestions to help me make this truly black?

Thanks!

Answer
Hello,
My apologies for the delay.
As far as I know, there really isn't an easy way to make sterling silver really black.
The methods you describe will make copper very black, but the silver content of sterling stops the full black.
You might notice that the black is a brown black, whereas vapour etching with ammonia will make gilding metal - red brass - a very black that is a blue black.

Actually the blackest silver I have ever achieved is with a Jax product called Silver Blackener and its made from Hydrochloric and tellerium dioxide.

Sorry I cant be of better help.......

The best black I've ever achieved - and the hardest wearing - is using aluminium and anodising it.
I use this process for making spectacles, and the finish is a bright lustrous deep black that looks like polished gemstone.....perhaps you want to head down this track.

Cheers and Good Luck, P