metamorphic
Likely weathered limestone or marble fragment
Calcite-rich carbonate rock; likely calcitic marble (CaCO₃), though limestone is also possible
AI-generated identification · may be incorrectPale gray-white, dull to weakly sugary luster, massive and fine-grained with irregular fracture; calcite hardness is Mohs 3 and reacts vigorously with dilute hydrochloric acid or vinegar. The bluish cast appears photographic lighting or surface weathering rather than diagnostic color.
Identified More metamorphic →
Explore Likely weathered limestone or marble fragment in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray-white, dull to weakly sugary luster, massive and fine-grained with irregular fracture; calcite hardness is Mohs 3 and reacts vigorously with dilute hydrochloric acid or vinegar. The bluish cast appears photographic lighting or surface weathering rather than diagnostic color.
Formation & geological history
Carbonate sediment deposited in marine environments later lithified as limestone; if recrystallized, heat and pressure produced marble. Such rocks range from Paleozoic to Cenozoic in age depending on locality.
Uses & applications
Commonly used for cement, aggregate, lime, dimension stone, and decorative marble; this small weathered fragment has little commercial value.
Geological facts
Calcite-rich material can often be scratched with a steel knife and leaves a white streak. Marble may show interlocking crystalline grains, whereas limestone commonly preserves fossils or visibly clastic textures.
Field identification & locations
Test an inconspicuous spot with dilute acid, inspect with a hand lens for fossils or interlocking grains, and compare hardness with a steel nail. Common worldwide, especially in former shallow-marine basins and metamorphic belts.
More like this
