igneous
Amygdaloidal Basalt
Vesicular Basalt with Mineral Infills
AI-generated identification · may be incorrectHardness 6-7 for infills and 5-6 for basalt matrix, dark gray to black color with white or pastel rounded mineral pockets, dull to vitreous luster.
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Physical properties
Hardness 6-7 for infills and 5-6 for basalt matrix, dark gray to black color with white or pastel rounded mineral pockets, dull to vitreous luster.
Formation & geological history
Formed from volcanic lava flows where gas bubbles create cavities that later fill with secondary minerals like quartz or zeolites from hydrothermal fluids.
Uses & applications
Used in crushed stone for construction, aggregate, and as collectible specimens for mineral enthusiasts.
Geological facts
The rounded mineral fillings are called amygdules, which can include agates, zeolites, or calcite depending on the local groundwater chemistry.
Field identification & locations
Identify by a dark, fine-grained volcanic matrix peppered with distinct rounded spots or cavities. Found worldwide in ancient and modern volcanic regions.
