As an average delivery time takes between 1 and 2 weeks.
Oxidized silver: A special kind of tincture is applied onto the silver, this causes an extreme oxidizing of the material. It is not harmful at all. Neither to your skin, nor to your clothing.
First black than anthracite, this effect will use off after wearing the piece, how fast depends on how you wear the jewel. We think though, this used-look just makes the jewel look even more charming, instead of being a loss of quality. Oxidizing the jewel again can be done at any time.