Crossbone Studs

Oxidised:

This finish has a dark grey hue and is fully oxidised with liver of sulphur that will rub away over time to an antique finish with wear (you can maintain oxidisation with a few tools, check here) Here are some examples of this finish;

Antique Matte:

This finish has been oxidised, but most of the oxidisation has been rubbed away so that the silver (or bronze) shows through and the crevices have an antique time worn look to them. The metal isn't shiny but has a matte feel. It will slowly shine up over time with wear. Here are some examples of antique matte finish;

Antique Polished:

Like antique matte, the piece has been oxidised, and rubbed away to have an antique like finish, but this option has a shiny finish rather than matte, and the silver (of bronze) shines through just a bit more. Here are some examples of antique polished jewellery;

Bright Silver Polished:

This finish has no oxidisation, and has been polished to a bright white silver shine (or bronze/gold depending on your custom metal choice). 
Although this option isn't usually available in my listings, if you ask for it I am happy to do it on nearly any of my items.