Why is my mummy blue?
June 7, 2025 12:21 AM Subscribe
Recreating the first synthetic pigment, Egyptian Blue circa. 3100BC / 5050BPE. Weaving archaeology, materials science, and lots of chemistry and coloured light, and unearthing many modern applications. Fulltext very readable and graphical paper here [ 8Mb pdf ].
My original title was going to be The chariots of the gods are painted blue as this amazing colour was so widely used across MENA "chariot" "egyptian blue"
My original title was going to be The chariots of the gods are painted blue as this amazing colour was so widely used across MENA "chariot" "egyptian blue"
First synthetic pigment was of course blue: as George Carlin once demanded, "Where's the blue food?"
posted by Aardvark Cheeselog at 7:28 AM on June 7
posted by Aardvark Cheeselog at 7:28 AM on June 7
Cuprorivaite [mindat] does occur naturally, although it does sound quite rare. Some pretty blue crystals at that link.
Preparing natural lapis lazuli sounds like an extreme pain. Joumana Medlej's Blue of Blues shows how its done. It's slow and very, very sticky.
posted by scruss at 7:43 AM on June 7 [2 favorites]
Preparing natural lapis lazuli sounds like an extreme pain. Joumana Medlej's Blue of Blues shows how its done. It's slow and very, very sticky.
posted by scruss at 7:43 AM on June 7 [2 favorites]
I made a a copy of this painted jar strand in the British Museum. It was cool to see on the original that blue the pigment was still a vibrant ultramarine where the dull, greenish crust had flaked away.
I wish there was more study into the binders used in these paints. I've read a study mentioning plant sugars, plant resins (gum Arabic) and animal glue protein, egg and honey and but none of these are waterproof. I've read about beeswax being used as a varnish in tomb paintings and Roman era wax-encaustic portraiture but there's not much to explain how painted household furniture stood up to moisture. On my copy, I used hot animal glue with some powdered pigments I bought in Berlin and got a somewhat sloppy result but in my defence , the original was pretty sloppy too.
posted by brachiopod at 11:06 AM on June 7 [7 favorites]
I wish there was more study into the binders used in these paints. I've read a study mentioning plant sugars, plant resins (gum Arabic) and animal glue protein, egg and honey and but none of these are waterproof. I've read about beeswax being used as a varnish in tomb paintings and Roman era wax-encaustic portraiture but there's not much to explain how painted household furniture stood up to moisture. On my copy, I used hot animal glue with some powdered pigments I bought in Berlin and got a somewhat sloppy result but in my defence , the original was pretty sloppy too.
posted by brachiopod at 11:06 AM on June 7 [7 favorites]
On the other end of the equation, we have... mummy brown. People get weird about colors. Weeeeeird.
posted by phooky at 1:10 PM on June 7 [1 favorite]
posted by phooky at 1:10 PM on June 7 [1 favorite]
It's important to differentiate a pigment from a dye.
Mauvine, the first synthetic dye, was made by William Perkin in 1856, accidentally, - thus- launching the modern chemical industry in Britain. Chemists were still arguing about its exact formulation in 2017.
posted by lalochezia at 2:23 PM on June 7 [1 favorite]
Mauvine, the first synthetic dye, was made by William Perkin in 1856, accidentally, - thus- launching the modern chemical industry in Britain. Chemists were still arguing about its exact formulation in 2017.
posted by lalochezia at 2:23 PM on June 7 [1 favorite]
I always assumed Lapis Lazuli owed its blueness to copper, but it doesn’t. It’s blue due to Sulfur in a +3 oxidation state in a silicate.
I wish there was more study into the binders used in these paints. I've read a study mentioning plant sugars, plant resins (gum Arabic) and animal glue protein, egg and honey and but none of these are waterproof. I've read about beeswax being used as a varnish in tomb paintings and Roman era wax-encaustic portraiture but there's not much to explain how painted household furniture stood up to moisture.
Brachiopod, I don’t know how the Egyptians did it, but I think I see a way they could have done it, and I believe you could probably do it that way too.
The fact that the blue principle of lapis is a silicate makes me think you could mix it with another silicate, namely sodium silicate dissolved in water, AKA water glass, and water glass is thought to have been produced by Egyptians more than 5000 years ago.
But water glass can also be a waterproof sealant even though it’s water based because it can polymerize after it’s applied. I read just now that it will polymerize in alkaline conditions, and it’s pretty alkaline itself (pH 11.2). But raw wood tends to be slightly acidic, so you might need to dress the wood somehow, but I’m not sure.
Ethanol will also cause water glass to polymerize, and there’s a commercial wood finishing product out of Japan called Liquid Glass that takes advantage of this property.
My guess is that either one of these approaches would produce a transparent waterproof finish that would last indefinitely and never yellow.
posted by jamjam at 2:52 PM on June 7 [4 favorites]
I wish there was more study into the binders used in these paints. I've read a study mentioning plant sugars, plant resins (gum Arabic) and animal glue protein, egg and honey and but none of these are waterproof. I've read about beeswax being used as a varnish in tomb paintings and Roman era wax-encaustic portraiture but there's not much to explain how painted household furniture stood up to moisture.
Brachiopod, I don’t know how the Egyptians did it, but I think I see a way they could have done it, and I believe you could probably do it that way too.
The fact that the blue principle of lapis is a silicate makes me think you could mix it with another silicate, namely sodium silicate dissolved in water, AKA water glass, and water glass is thought to have been produced by Egyptians more than 5000 years ago.
But water glass can also be a waterproof sealant even though it’s water based because it can polymerize after it’s applied. I read just now that it will polymerize in alkaline conditions, and it’s pretty alkaline itself (pH 11.2). But raw wood tends to be slightly acidic, so you might need to dress the wood somehow, but I’m not sure.
Ethanol will also cause water glass to polymerize, and there’s a commercial wood finishing product out of Japan called Liquid Glass that takes advantage of this property.
My guess is that either one of these approaches would produce a transparent waterproof finish that would last indefinitely and never yellow.
posted by jamjam at 2:52 PM on June 7 [4 favorites]
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posted by HearHere at 2:26 AM on June 7