Blue Verditer Pigment
Blue Verditer is the name given to artificial basic copper carbonate with approximately the same chemical composition as azurite. Refiner's dark blue verditer was used in watercolors and distemper during the 17th and 18th centuries. Our Refiner's dark blue verditer is made according to an English recipe of the 18th century.
|Common Names:||English: blue verditer
French: verditer bleu
German: blau verditer
Italian: blu verditer
Spanish: azul verditer
|Synonyms:||English: bice; blue ashes, cendres blue, Sanders blue; mountain blue, copper blue, lime blue
French: cendres bleu; bleu de montagne; bleu d'Allemagne
German: Verditer; Aschblau; Bergblau; Kalkblau
Italian: ceneri blu di pasta, azzurro della cenere; azzurro della magna
Portuguese: azul da cinza; azul da montanha
Spanish: azul de la ceniza; azul de la montaña
Latin: lapis armenius; azurium citramarinum
|Pigment Classification:||Synthetic Inorganic|
|Colour Index:||Pigment Blue 30 (PB30)|
|Chemical Name:||Basic Copper Carbonate|
|Particle Size (mean):||5 microns|
|Refractive Index:||α=1.73, β=1.758, γ=1.838|
|Oil Absorption:||23 grams oil / 100 grams pigment|
|Health and Safety||Copper carbonate is classified as hazardous under OSHA regulations (29CFR 1910.1200) (Hazcom 2012):
Acute toxicity—Oral—Category 4
Skin irritant—Category 2
Eye irritation—Category 2A
Based on this information we present the following health warning:
WARNING! Contains Copper Carbonate. Harmful if swallowed. Causes skin irritation. Causes serious eye irritation. Avoid ingestion, excessive skin contact, and inhalation of dusts. Conforms to ASTM D-4236.
For a detailed explanation of the terms in the table above, please visit Composition and Permanence.
Origin and History
Blue verditer is the name given to artificial basic copper carbonate with approximately the same chemical composition as azurite. It is believed that blue verditer was a byproduct of silver refining. Numerous early recipes for its preparation are known; the best types appear to have been prepared at relatively low temperatures with a copper salt. "Refiner’s verditer" was considered the best type of copper carbonate and was widely used as house paint during the 17th and 18th centuries with continuing use up to the 19th century.
Our Refiner's dark blue verditer is made according to an English recipe of the 18th century that requires relatively low temperatures for its manufacture. This deep blue, slightly more greenish than natural azurite, lends itself well to consistent applications of color. Microscopically, blue verditer appears as tiny, rounded, fibrous aggregates, even in size and blue by transmitted light. It is similar in color to finely ground azurite.
Permanence and Compatibility
Blue verditer is stable in lime and is well suited for tempera and watercolor, but is liable to darken or become greenish in oil. However, it can be used with some success if it is mixed with lead white ground in oil. The white pigment lightens the blue and keeps it from appearing too dark. Painted swatches of our Refiner's dark blue verditer ground in oil show little change in color after five years.
Oil Absorption and Grinding
Verditer absorbs a medium amount of oil (23 g oil per 100 g of pigment).
Blue verditer contains copper, which can be toxic if inhaled or ingested. Care should be used in handling the dry powder pigment to avoid inhaling the dust.
For more information on how to handle pigments safely, please visit How to Safely Handle Art Materials and Pigments.
|Processing Time||Orders ship on Tuesdays and Thursdays.|
|Pigment Type||Inorganic, Historical, Synthetic|