EPIDOTE associated with QUARTZ (large cabinet)

Epidote, with the chemical formula Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), commonly forms well-developed crystals that belong to the monoclinic system. These crystals typically exhibit a prismatic shape, with their elongation occurring perpendicular to the single plane of symmetry.

Epidote is a mineral composed of calcium aluminium silicate hydroxide with the chemical formula Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH) and is categorized as a sorosilicate which commonly forms well-developed crystals that belong to the monoclinic system. These crystals typically exhibit a prismatic shape, with their elongation occurring perpendicular to the single plane of symmetry.

It is commonly found in metamorphic rocks, typically forming through the alteration of plagioclase feldspar, pyroxenes, and amphiboles during contact metamorphism and hydrothermal processes. Additionally, epidote can be present in basalt and granite formations. It serves as a significant rock-forming mineral, notably in two types: epidosite, which consists of epidote and quartz, and unakite, which combines epidote with pink orthoclase. Although the locations of these rocks are relatively rare, they can contain substantial amounts of epidote.

The mineral was named by René Just Haüy in 1801, deriving its name from the Greek word "epidosis," meaning 'increase,' due to the distinctive elongation of one side of its crystal prism. A notable characteristic of epidote is its remarkable pleochroism, allowing it to exhibit different colors when viewed from various angles.