
mineral
Small pale mineral fragment, likely quartz or calcite
Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing
AI-generated identification · may be incorrectWhite to cream, opaque, dull-to-vitreous luster, irregular granular fracture; quartz hardness 7 with no cleavage, while calcite is hardness 3 and has prominent rhombohedral cleavage. Specific gravity is approximately 2.65 for quartz or 2.71 for calcite.
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Physical properties
White to cream, opaque, dull-to-vitreous luster, irregular granular fracture; quartz hardness 7 with no cleavage, while calcite is hardness 3 and has prominent rhombohedral cleavage. Specific gravity is approximately 2.65 for quartz or 2.71 for calcite.
Formation & geological history
Could derive from weathered quartz vein, quartz-rich rock, or limestone/marble. These minerals formed in many geological settings ranging from hydrothermal veins to sedimentary and metamorphic environments; age cannot be determined from the image.
Uses & applications
Quartz is used in glass, electronics, abrasives, and engineered stone; calcite is used in cement, lime, soil treatment, and as a mineral specimen. This fragment is too small and uncharacteristic for significant jewelry value.
Geological facts
A steel knife or glass test can help distinguish them: quartz resists scratching by steel and can scratch glass, whereas calcite is easily scratched. Calcite also effervesces with dilute hydrochloric acid.
Field identification & locations
Common worldwide, especially in quartz veins, granitic terrains, limestones, and marbles. Test hardness, cleavage, and acid reaction before naming it confidently.