The Bologna Stone, called Lapis Solaris ("sun stone") by early investigators, is a barite mineral found near Bologna, Italy and discovered around 1602 by the shoemaker and alchemist Vincenzo Cascariolo to glow after exposure to sunlight, one of the earliest documented phosphorescent substances studied in the West. Its glow, initially attributed to a captured solar essence in keeping with contemporary alchemical thought before later chemistry explained it as a genuine phosphorescent property of the calcined mineral, made it a celebrated curiosity discussed by natural philosophers across Europe and a standard example among the classified "earths" of the period.
Facts
Method
Preparation MethodThe raw barite mineral is calcined (roasted); the phosphorescent glow after exposure to sunlight is a property of the calcined stone, not of the raw mineral. 1 Attestation
Earliest Attestationc. 1602, Vincenzo Cascariolo 1 Physical Description
Chemical FormulaBaSO4 (barite, barium sulfate). 1 Connections
Associated With
This source names Europe directly: "by natural philosophers across Europe and a standard example among the classified "earths" of the period."
Source Nature's Building Blocks: An A-Z Guide to the ElementsJohn Emsley
This source names Italy directly: "a barite mineral found near Bologna, Italy and discovered around 1602 by the shoemaker and alchemist Vincenzo Cascariolo to glow after exposure to sunlight, one of the earliest documented..."
Source Nature's Building Blocks: An A-Z Guide to the ElementsJohn Emsley
Composed Of
Its own text names it a barite mineral (BaSO4).
Source Mindat.org - The Mineralogical ReferenceHudson Institute of Mineralogy
Its own text names it a barite mineral (BaSO4).
Source Mindat.org - The Mineralogical ReferenceHudson Institute of Mineralogy
Its own text names it a barite mineral (BaSO4).
Source Mindat.org - The Mineralogical ReferenceHudson Institute of Mineralogy
Related To
Sources
1. Nature's Building Blocks: An A-Z Guide to the Elements
John Emsley, Oxford University Press, 2011on the Bologna Stone and early phosphorescenceView the Source Reader Challenges (0)
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