page_title: Euhedral and anhedral
hierarchical_section_title: Euhedral and anhedral
caption_attribution_description: English: Pyrargyrite Locality: Zacatecas, Mexico (Locality at mindat.org) Size: 3.0 x 2.9 x 0.9 cm. A fine radial fan of lustrous, sharp to anhedral pyrargyrite crystals around a core of quartz from the silver mines of Zacatecas, Mexico. Unusual formation and shape. The sharp crystals show flashes of the classic, ruby silver color under good light. Ex. Jaime Bird and Miguel Romero Collections. An excellent provenance for this excellent specimen. Deutsch: Pyrargyrit Fundort: Zacatecas , Mexiko (Fundort bei mindat.org) Größe: 3.0 x 2.9 x 0.9 cm.
context_page_description: Euhedral crystals are those that are well-formed, with sharp, easily recognised faces. The opposite is anhedral: a rock with an anhedral texture is composed of mineral grains that have no well-formed crystal faces or cross-section shape in thin section. Anhedral crystal growth occurs in a competitive environment with no free space for the formation of crystal faces. An intermediate texture with some crystal face-formation is termed subhedral.
  Crystals that grow from cooling liquid magma typically do not form smooth faces or sharp crystal outlines. As magma cools, the crystals grow and eventually touch each other, preventing crystal faces from forming properly or at all.
  When snowflakes crystallize, they do not touch each other. Thus, snowflakes form euhedral, six-sided twinned crystals. In rocks, the presence of euhedral crystals may signify that they formed early in the crystallization of magma or perhaps crystallized in a cavity or vug, without hindrance from other crystals.
context_section_description: Euhedral crystals (also known as idiomorphic or automorphic crystals) are those that are well-formed, with sharp, easily recognised  faces. The opposite is anhedral (also known as xenomorphic or allotriomorphic): a rock with an anhedral texture is composed of mineral grains that have no well-formed crystal faces or cross-section shape in thin section. Anhedral crystal growth occurs in a competitive environment with no free space for the formation of crystal faces. An intermediate texture with some crystal face-formation is termed subhedral.
  Crystals that grow from cooling liquid magma typically do not form smooth faces or sharp crystal outlines.  As magma cools, the crystals grow and eventually touch each other, preventing crystal faces from forming properly or at all.
  When snowflakes crystallize, they do not touch each other. Thus, snowflakes form euhedral, six-sided twinned crystals. In rocks, the presence of euhedral crystals may signify that they formed early in the crystallization of magma or perhaps crystallized in a cavity or vug, without hindrance from other crystals.
caption: Sharp to anhedral pyrargyrite crystals--a subhedral sample.
exif: {}