Agate is a microcrystalline variety of the quartz group, a type of chalcedony of various colors that usually presents chromatic bands. There are many types of agate, its color depends on the different materials it may contain. The most abundant are gray, but we also find them in yellow, orange, white, blue, brown and pink.
Being a porous mineral, sometimes it can be dyed with bright colors, as in the case of fuchsia agate, deep blue agate or dark green agate.
Agate in its natural state usually occurs as inclusions within ovoid or spherical cavities of volcanic rocks. When an agate geode is opened, crystallizations of quartz, amethyst or calcite usually appear inside.
Its hardness is 7 on the Mohs scale and it can be translucent or opaque, depending on its thickness.
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