Agate is a transparent or translucent form of chalcedony, characterized by distinctive color banding, often arranged in concentric patterns. Often, non-banded chalcedony with various mineral impurities - such as moss, plume, or flame patterns - is also classified as agate.

The gemstone's name originates from the Achates River (now Dirillo) in Italy, where agates were first discovered. Unique inclusions make agates highly prized; varieties like “angel wing” agate, dendritic, sagenitic, moss, and plume agates are particularly valued.

Agate colors span a broad range, including white, gray, orange, brown, pink, green, purple, black, yellow, and multicolored tones, with rare hues like green and blue. Iron oxides mainly drive these colors, while other elements—such as manganese, chromium, celadonite, nickel, copper, and hematite—contribute to different hues.

Agate Identification Guide

Agate vs Jasper

Agates and jaspers are often confused due to their similar appearances, as both are varieties of chalcedony. However, their classification depends on the inclusions and patterns present in the mineral.

Jasper typically has a solid color or a cloudy appearance, while agate is generally translucent (light passes through, but you can't see through it completely).

Agates are characterized by concentrically banded patterns, whereas jasper features spots or stripes.

In terms of color, agates can be multicolored and are commonly found in white, gray, orange, brown, pink, green, purple, black, and yellow, with green and blue hues being particularly rare. Jasper tends to be multicolored as well, but its colors are usually yellow, brick-red, brown, mottled green, and rarely blue.

Angel Wing Agate is lumpy, irregular, or botryoidal (grape-like) shaped material with a cross-section similar to plume agates.

Carnelian (“flesh” in Latin) Agate is colored by iron oxides and and characterized by red, orange, and brown hues. It is often found in rivers, shorelines, and mountains.

Dendritic (“tree-like” in Greek) Agate features tree-like or fern-like patterns formed by mineral impurities locked inside the agate. The base color is typically white, gray, or occasionally purple.

Enhydro (“water” in Greek) Agate, or Water Agate, contains tiny, movable bubbles of water or air trapped inside the stone.

Eye Agate forms when most of the silica gel drains from its cavity, leaving small droplets that crystallize into concentric "eyes" with additional layers of silica arranged around them.

Fortification Agate shows parallel banding that crystallizes in angular, concentric layers, resembling the aerial view of a fort.

Iris Agate produces a rainbow effect when held up to the light.

Moss Agate contains a group of dendritic growths. When these growths create an imaginative landscape scene, the stone is referred to as scenic or landscape agate.