Ultramarine ash

Ultramarine ash

Description

Ultramarine ash at 100x (visible light left; UV light right)

The end-product of the refining process used to produce natural ultramarine blue pigment from Lapis lazuli. Ultramarine ash contains small blue particles mixed with a large proportion of colorless materials, such as calcite and silicates. Ultramarine ash is a transparent blue-gray pigment that has been used for glazing.

Synonyms and Related Terms

mineral blue; Sander's blue; Saunder's blue; bleu cendres; vein stone

XRD

SEM

EDS

XRF

Risks

• No significant hazards.

Physical and Chemical Properties

• Discolors when exposed to weak acids or sulfur fumes.

Resources and Citations

• J. Plesters, "Ultramarine Blue, Natural and Artificial", Artists Pigments, Volume 2, A. Roy (ed.), Oxford University Press: Oxford, 1993.

• Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)