Known locally as a Squareback cluster for the square or cubed negative impressions left within the crystal's matrix. The Calcite crystals dissolved while underground, sometime after the quartz formed, leaving negative cubed or “square” impressions in the matrix. Relatively rare in the quartz family. The Squareback variety possess exceptional water clear crystals, often with beautiful gem clear starburst clusters forming off the main matrix.
This 4” water clear Squareback cluster was mined from Twin Creek Mine (Mt. Ida, AR) in July 2022. Weight is 232g (8.2 oz).
Unique features include:
1) Quartz Epimorph after Calcite cluster - Water clear crystals on a complex matrix where the matrix formed around Calcite cubed crystals. The dissolved minerals left many caverns. See bottom of description for detailed definition.
2) There are 6 primary water clear points with pristine tips and pronounced striations.
3) Largest point measures 1.75” tall and .75” wide with a small point penetrating from the main point's side. The smaller penetrator point also intersects the tip of a third point.
4) Fairy Frost coats the faces of the two lateral twin points
5) A tiny, left-slanted window is visible on the center point within the small fan-shaped cluster in the back
6) Internal rainbows are present when light passes through internal fractures
QUARTZ EPIMORPH AFTER CALCITE (aka locally SQUAREBACK MATRIX) - Sometimes called epimorphs or perimorphs. Epimorphs are a type of pseudomorph where a mineral replaces another mineral and the original mineral dissolves, leaving a hollow cast surrounded by the new mineral. The online epimorph quartz mineral can form around another mineral(s) such as calcite, leaving the shape of the mineral when it dissolves. This dissolution most often occurs through exposure to naturally occurring acidic solutions.
Our crystals are naturally formed, unpolished and without repairs. The pictures are of the actual crystal you will receive. Weight is 232g (8.2 oz).
Product code: 4" Clear Arkansas Quartz online Epimorph after Calcite Cluster