In addition to natural impurities, glass is colored by purposely introducing minerals or purified metal salts (pigments). 7-8;7;7

In Pliny's time this rock, quarried in Egypt, was used extensively for architectural and ornamental purposes, and especially for the base or lower part of busts To the Italians it became known as porfido rosso anlico. (Lansco), Perylene dyes are a group of red and violet synthetic organic vat dyes discovered about 1912. Cadmium Litho Red Medium Light Xtra [GU]; Cadmium Litho Scarlet Xtra (yellow shade) [GU]; Cadmium Maroon LITHO (violet shade) [GU]; Cadmium Red Dark LITHO (blue shade) [GU]; Cadmium Red Dark Xtra LITHO (blue shade) [GU]; Cadmium Red Light (hue*) [BR | BA.a | ROSS.o]; Cadmium red light LITHO (orange shade) [GU]; Cadmium red light LITHO (yellow shade) [GU]; Cadmium Red Medium (hue*) [BR | CL | BA.a | DSd | ROSS.o]; Cadmium Red Medium Light Xtra LITHO (blue shade) [GU]; Cadmium Red No. Suggest making your own tests.

Probably not a big hazard to humans, as there is very little soluble mercury.

Phosphotungsto

@ Blick Art Materials); also see (Ref.

; **Fluorescent paints are not recommended for permanent art work unless it will be completely protected from light. if (! NB = Natural Blue;

(Ref), Highly hydraulic volcanic pumice from Umbria, Italy. ; "evolved from work done at the University of Texas-El Paso to reconstruct the unique vibrant blue color developed by the Maya civilization more than 1000 years ago, using an inorganic and organic component to produce a highly stable hybrid pigment.".

(Epsilon); * Lightfastness rated II (very good) in watercolors by handprint, only one formulation tested. 7-8; 7 Cadmium Red Purple Light Substitute [SE.p]; BWS

May be effected by very basic or very acidic  conditions (Ref. Fades = Loses chroma and becomes more Transparent Paint and Coating Testing Manual: 14th ed. Synthetic Anhydrous red iron oxide, It may consist of the additional modifiers Cr2 03, FeO, Mn203, or/and NiO in any combination.

From my experience the transparent types are more often used in artist's paints, but some paint makers may use the opaque versions. Pink clay stone consisting of Iron Oxide and Clay, Was used by Native Americans to make sacred pipes. See below PR-108:1 for more info on cadmium barium pigments, and why it matters.

7-8; 6-7; 5 Mordant red 9 co-precipitated on Alum hydroxide base with barium chloride; lightly staining w/ adverage tiniting strength. PM = Pigment Metal. (Ref Pigment Compendium, 2008, p.177); Egyptian Red Gold may be a corrosion product article at The Metropolitan Museum of Art's website (Ref).