Black Agate Polished Tumble Stones
Black Agate is used for grounding and protection.
Agate can be of any colour, but the most frequent colours are grey, white, brown, salmon, pink, red, orange, black, and yellow. Shades of violet or a greyish-blue can occur, deep green and blue tones are very unusual . The colour is caused by various embedded minerals, of which iron oxides and hydroxides are most common, giving yellow, brown and red colours. A "pure" agate is white, grey or blue-grey.
Agate has long been known as a porous material that can be dyed easily and numerous methods to change, enhance or add colour have been developed. Specimens that lack vivid colours and banding, like many agates from Brazil, are cut into thin slices and artificially "enhanced" with various dyes, yielding deep green, bright blue and bright pink.