This color contains the following pigments:
PR101-Red Iron Oxide
manganese ammonium pyrophosphate
(NH4)2Mn2(P2O7)2 - Mn3(PO4)2 * 3H2O or H4O7P2H3NMn
Manganese Violet is a semi-transparent, bluish-violet pigment with a discrete opacity and low tinting strength. It is the reddest of the violets, and it covers and dries well in oil and tempera. It also performs well in pastel, encaustic, and watercolor. Manganese Violet is not well suited for fresco or acrylic painting. There can be significant differences in color across brands. It shares similar properties with bluish shades of Cobalt Violet.
Manganese Violet has excellent permanence and lightfastness, and it is one of the most lightfast, balanced violets in watercolor form.
Manganese Violet is highly toxic if inhaled and moderately toxic if ingested.
This pigment was developed in 1868 by E. Leykauf to replace the more expensive Cobalt Violet. It was not offered as an artists’ pigment until 1890.
PR101-Red Iron Oxide
iron oxides (synthetic), iron oxide, silica, alumina, lime, and magnesia or hydrated iron oxide
Fe2O2 or Fe2O3 • H2O
Red iron oxide varies in hue and transparency, depending on hydration and slight impurities. Indian Red is a slightly duller, deep brick hue with a bluish undertone. It is very dense and opaque, with excellent tinting strength and covering power. It is dependable when mixing with all other permanent pigments and yields good flesh tints when mixed with Zinc White. It is the synthetic version of PR102, which is a pigment made from earth reds, or natural red iron oxides, and the names applied to PR101 and PR102 often overlap. The synthetic red iron oxides have mostly replaced natural red iron oxides and are brighter, stronger, finer, and more permanent. Indian Red is the highest grade bluish shade. Light Red, English Red, and Venetian Red are yellowish shades. Mars Violet is a dull and subdued bluish or purplish oxide.
Red iron oxide is very lightfast with excellent permanence.
Red iron oxide has no significant hazards.
Natural red iron oxide comes from the mineral ore hematite, called bloodstone by the ancient Greeks from the word hema, meaning blood. It is one of the oldest pigments, has been used by every major civilization, and was an important mineral for medieval alchemists. It was not widely used in artists' materials until the 17th century and was not produced in large quantities until the 18th century.