Things you will need:
- Something to scrub your jewellery with, like an old toothbrush
- Something to fish your jewellery out of the container with, maybe a piece of wire in a hook shape or plastic tweezers, anything really.
- Liver of sulphur (gel kind is best) I got mine from Cool Tools
- Warm water
- Baking soda
- A non-porous container/jar x 2
- A well ventilated area
- Protective eye wear, apron and gloves *optional if yolo*
So you have a lovely and bright piece of sterling silver or any other copper alloy jewellery and you want it black, like your heart? No problemo friend, I am here to help.
First things first you need to clean your jewellery. Use the toothbrush/nail brush or whatever else kinda brush you have that will scrub in the nooks. Use it with dish soap to get rid of any hand grease or grimes. Ultrasonic cleaners also do this job for you.
Next, take your containers (I use old jars) and fill them with enough warm water to cover the object. In one, dump a couple teaspoons of baking soda - this is your neutralising solution to stop the oxidation. In the other squeeze a 1/4 tsp (eyeball it) of the liver of sulphur gel. Mix well and wait for that pungent aroma to make you gag - it is rotten eggs. It should turn a very yellow colour.
Image courtesy of http://www.fullmetalbeauty.com/blog/category/studio
Use the instrument you've chosen to fish your jewellery out of the jar and use it to lower your piece into the LOS concoction. I like to use a thin piece of copper wire in a hook shape and just bend it over the jar as it oxidises. Depending on how oxidised you want the piece will depend on how much LOS you put in as well as how hot the water is. If the water is boiling it will turn black instantly. If you want a gun metal look then luke warm water and less LOS and constant monitoring is needed. The change will happen very fast so keep a watchful eye. Don't get it on your skin...if you are clumsy use gloves, this stuff stinks and you will smell like The Bog of Eternal Stench if you get it anywhere on you.
Lower your piece into the LOS and remove it just before it is the shade you want it to be, immediately drop it into the neutralising jar of baking soda and swirl around. Leave it in there for a minute.
Take the piece out, if it's not the shade you wanted and it needs to be darker then just immerse in the LOS again until you get the desired effect.
Copper is a really cool metal to work with, you can get so many crazy shades if you have a deft hand. I've created rainbows and golden colours on some past copper jewellery. Silver can be from a medium grey to a black.
The oxidation will matte the jewellery and you can bring it up to the polish underneath the patina by using a soft cloth and buffing it gently. Make sure it's not a cloth with a polishing compound in it or you'll just take off all your hard work. Of course, this is also a cool effect, polishing the high points of the piece and leaving the recesses dark adds depth to the piece.
Here I have oxidised the full piece and then buffed off one or two of the prongs back to shiny silver.
Now, because we are earth and animal conscious here at Callirrhoe Jewellery DON'T just dump the LOS solution down the drain. It is TOXIC to plant life/aquatic life as it is. You need to neutralise it. Pour the baking soda solution into the LOS and if you are in a hurry, add more baking soda to the LOS. You are looking for it to turn a very cloudy light colour, this means it is neutralised. I just leave mine outside the studio for a few days until it turns white and then pour it into some garden plants. Hasn't killed any yet haha.
If you want to keep the patina lasting longer, purchase something like Protectaclear by Everbrite. It's a skin-safe coating that doesn't change the finish of the piece but will invisibly coat your jewellery (probably don't use it on a chain). I also use carnauba wax as less chemical protector. I buff it onto the piece with a cotton mop and pendant drill. It does make the piece shiny though and not everyone likes that look.
Fear not making mistakes though as all of this is temporary, the more you wear your pieces the quicker they will wear off the patina.
Anyway, I hope you found that helpful! Next I'll be doing a blog entry on how to remove patina/oxidation/tarnish from jewellery using various methods.