- Red Jasper is an amorphous quartz, colored red by iron (III). Glass-like transparency and high brilliance in historical
dye films is frequently produced by Red Jasper. Sometimes in analysis the pigment might have been confounded with
In small occurrences Red Jasper is fairly common. In the Alps there is a modification, called radiolarian rock. The
frequency of use probably depended upon the hardness of the mineral.
Amorphous quartz colored red by iron-(III).
The glassy translucency and high brilliance often suggests red jasper in historical color layers. Now and then the pigment has been mistaken for realgar in analysis. Semi-transparent, sandy texture, silicon oxide SiO2
- Chemical description: Natural product.
- Chemical Formula: SiO2
- Lightfastness – medium: 8 (1 is bad, 8 is best)
- Lightfastness – thinned: 8 (1 is bad, 8 is best)
- Lightfastness – concentrated: 8 (1 is bad, 8 is best)
- ColorIndex: PW 27.77811
- Suitability: Acrylics, Cement / Tadelakt, Lime / Fresco, Oil, Silicate binder, Waterglass, Tempera, Watercolor / Gouache
- Colors: Red
- Forms: powder
- Solubility in water: insoluble