Page "Agate" Paragraph 9

A Mexican agate, showing only a single eye, has received the name of cyclops agate.

Included matter of a green, golden, red, black or other color or combinations embedded in the chalcedony and disposed in filaments and other forms suggestive of vegetable growth, gives rise to dendritic or moss agate.

Dendritic agates have fern like patterns in them formed due to the presence of manganese and iron oxides.

Other types of included matter deposited during agate-building include sagenitic growths ( radial mineral crystals ) and chunks of entrapped detritus ( such as sand, ash, or mud ).

Occasionally agate fills a void left by decomposed vegetative material such as a tree limb or root and is called limb cast agate due to its appearance.