TTB59XXX: Botryoidal group, with intense luster and a smooth surface, accompanied by small white Calcite crystals that provide contrast with the Goethite.
It comes from a locality little known in collecting, which adds interest to the specimen, and it also preserves the pedigree of having belonged to the Harry Critchley collection, Critchley himself being the one who found the specimen.

Kremikovtsi is an important mining and metallurgical complex located northeast of Sofia, mainly known for its iron mineralization and mineral associations developed in skarn and metasomatic environments. Kremikovtsi Mine has produced specimens of Magnetite, Hematite, Goethite, Calcite, Quartz, sulfides, and various secondary minerals, some showing aesthetic crystallization and interesting mineral associations for collectors.

Geologically, the deposit is related to metasomatic processes developed through the interaction of hydrothermal fluids with host carbonate rocks, forming iron-rich skarn mineralization accompanied by calcium silicates, oxides, and sulfides. Fluid circulation and later alteration also favored the development of cavities with well-defined crystal growth and complex mineral associations.
Kremikovtsi Mine, Kremikovtsi, Stolichna Municipality (Sofia), Sofia-City Province (Sofia-grad)  Bulgaria (10/2003)

Specimen size: 8.1 × 5.5 × 3.6 cm = 3.19” × 2.17” × 1.42”