Quartz var. Jacinto de Compostela and Gypsum

Item Description

Impressive hedgehog-like spherical aggregates of scintillating brick-red quartz crystals are embedded in the large and sculptural clay-tinted marl matrix. The striking large compound hedgehog is 8.8 cm across. Jacinto de Compostela quartz is a rare style of quartz colored by clay inclusions, not hematite. Two types are found: 1. Isolated biterminated crystals, 2. hedgehog-like spheroidal aggregates. Both characteristically occur as "floaters" embedded in marl, or as inclusions in gypsum masses or, less commonly, aragonite crystals (MINDAT). See: https://www.mindat.org/min-27377.html for more information on this unusual variety of quartz. A 4.0 cm vug on the matrix hosts gypsum crystal sections, as a bonus. 1759 grams or 3.9 pounds mass. Ex Raul Sanabria Orellana Collection, a well-known Spanish collector and author. He is the co-author of the excellent recent 2024 Mineralogical Record Berbes, Spain article in Vol 55, No 1 and co-author of the 2021 Mineralogical Record article on the Aliva Mining District, Spain Vol. 52, No. 4. A large and excellent specimen of this strange looking varietal from the locality. Huge, rare, and fine for what it is!