What is Agate?


Agate is a variety of chalcedony that is characterized by its fine grain and bright colors. It’s one of the most common minerals on Earth and is primarily found in volcanic rocks. Agate has been used for thousands of years and is known for its incredible variety of patterns and colors.

Agate is a colorful, banded stone that belongs to the chalcedony family. Its wide range of colors and intricate patterns make it a popular choice for jewelry and decorative items. The stone is often used in rings, necklaces, and pendants, and is sometimes used to make beads.

Gemstone Properties

Chemical ClassificationInorganic - Silicate (Chalcedony)
ColorComes in a wide range of colors, including but not limited to blue, green, red, yellow, and brown. The colors often appear in bands.
LusterWaxy to vitreous.
TransparencyTranslucent to opaque.
OccurrenceBrazil, India, Uruguay.
FormationAgate is formed from the deposition of silica from groundwater in the cavities of igneous rocks.
Mohs Hardness6.5 to 7.
Specific GravityApproximately 2.58 to 2.64.
Diagnostic PropertiesBanded appearance with multiple colors.
Chemical CompositionSiO2
PleochroismNot exhibited in agate.
Crystal SystemHexagonal (variety of Quartz)
Optical PropertiesUniaxial (+)
Refractive Index1.530 - 1.539
2V angleNot applicable (isometric)
DispersionNot typically relevant for agate.