sedimentary
Picasso Stone
Metamorphosed Calcium Carbonate (Limestone)
Hardness: 3-5 Mohs; Color: Grey base with black, brown, or gold spider-web patterns; Luster: Vitreous to dull; Crystal structure: Trigonal; Cleavage: Good in three directions; Specific gravity: 2.71.
- Hardness
- 3-5 Mohs
- Color
- Grey base with black, brown, or gold spider-web patterns
- Luster
- Vitreous to dull
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Physical properties
Hardness: 3-5 Mohs; Color: Grey base with black, brown, or gold spider-web patterns; Luster: Vitreous to dull; Crystal structure: Trigonal; Cleavage: Good in three directions; Specific gravity: 2.71.
Formation & geological history
Formed through the deep-earth metamorphism of limestone (calcium carbonate). The distinctive line patterns are created by iron oxides and other minerals infiltrating the stone through cracks during the tectonic cooling process. This specimen appears to be a river-tumbled or mechanically polished pebble.
Uses & applications
Primarily used as a decorative stone in jewelry (beads, cabochons), small carvings, and as 'worry stones' or pocket stones. It is popular in metaphysical collecting for its artistic appearance.
Geological facts
Despite being called 'Picasso Jasper' in various commercial markets, it is geologically a marble/limestone rather than a jasper (which is silicate-based). It is named for its resemblance to the abstract brushstrokes found in modern art paintings.
Field identification & locations
Identify by its characteristic 'cracked' or 'mosaic' grey and black pattern and its relative softness compared to quartz. It reacts to dilute hydrochloric acid (effervescence) due to its calcium carbonate content. Commonly found in Utah, USA.
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