Petr Hykš: Doubravice quarry
Petr Hykš: Quartz & secondary calcite geode in permian vulcanite
Petr Hykš: Quartz & secondary calcite geode in permian vulcanite
Petr Hykš: Quartz & secondary calcite geode
Petr Hykš: Quartz & secondary calcite geode
Petr Hykš: Chrysocolla
Petr Hykš: Amygdaloidal permian vulcanite
Petr Hykš: Amygdaloidal permian vulcanite
Petr Hykš: Chalcedony layers & quartz crystals filled amygdaloidal permian vulcanite
Petr Hykš: Agates in permian vulcanite
Petr Hykš: Amygdaloidal permian vulcanite
Petr Hykš: Beautiful agate (as found)
Petr Hykš: Agate
Petr Hykš: Amethyst
Petr Hykš: Magmatic rocks, very old lava flows