The Cave in Colour ?

The earliest known paintings have been found in caves in Indonesia and could date back to as early as 45000 BC. Early pigments were taken from organic sources; the main compounds from iron, clay, manganese dioxide and silica. These would produce earthy colours such as sienna, umbers and ochres. Later, natural minerals were used to produce blues and green.

Verdigris would be taken from copper, which was produced after the metal had been exposed to wine or urine. The powder was collected and mixed with animal fat, oil or even honey. Later in the 13th century, a water and egg tempura mix was used.

Ultramarine blue, at one time more expensive than gold, was produced when the gemstone Lapis Lazuli was ground.  First used in the 6th century by Buddhist monks, these gems stones were exported from Afghanistan, but it wasn’t until the 14th century that Italian traders began to bring this precious commodity to Europe.

In Mexico they would obtain Cochineal red by crushing insects, whilst in Europe vermillion red was produced from cinnabar mineral, the principal ore of mercury.

Manufactured, synthetic pigments were discovered by early alchemists and scientists.

Prussian Blue was discovered by accident in the early 1700’s by Johann Dippel. When potash, contaminated with blood, was mixed with cochineal insects and iron sulphate, it produced blue instead of red.

In 1826 a synthetic ultramarine was invented by Jean Baptiste Guimet, who made it by heating kaolinite, sodium carbonate and sulphur together. These synthetic alternatives made paint cheaper to buy and more available.

Wall paintings, often seen in churches, were either fresco or secco. The fresco method of painting uses a water-based pigment which is applied to freshly applied plaster. The colours would dry and set with the plaster to become a permanent part of the wall. The secco process involved the walls being soaked with limewater and painted while still wet. With this method the colours do not penetrate the plaster but form a surface film.

The use of colour could mark a difference and distinction between occupation, status, religious or political affiliations, and there were specific significances when used in religious paintings.

Green was an indicator of new life, fertility and rebirth and was often used in crucifixion scenes from the 11th century onwards. Red represented not only the flames of hell but also the power of the Holy Spirit. Medieval artists would use red rays to symbolise divine energy transferred from heaven to earth. Blue had links to the divine and may have been used to denote the Virgin Mary due to its expense and rarity.

There are accounts that have been written about the carvings within Royston Cave, which suggest that some may have originally been painted.

The first person to write about the cave was Rev G North in 1742. He wrote to William Stukeley about the initial discovery describing the carvings on the wall but did not mention that any were coloured with pigmentation.

Stukeley himself, in his Palaeographia Britannica, only vaguely mentions that William Lilly, who helped remove the soil from the cave, commented that the figures of the priory seal were painted red, and that he himself saw the remains.

It wasn’t until 1858, when The Origin and Use of Royston Cave was published by Joseph Beldam, that more details about paint colour are described. He stated about the carvings;

‘Many of these, if not all, have been coloured. Vestiges of red, blue, and yellow are visible in various places; and the relief of the figures has been assisted by a darker pigment’.

Other references that Beldam made of the colours seen in the cave include this extract about the ‘resurrection’ carving.

‘Tomb recess cut into wall painted dark blue, figure in the tomb painted yellow. The figure laying on an arm of which it was painted red. And hand of God red.’

When describing the masonry which partially block the eastern shaft he said,

 ‘The two lower courses only of this masonry now remain, formed of blocks of chalk neatly chiselled, and coloured red, giving them the appearance of brickwork.’

He also states that the priory seal figures, and the figure now thought to be St George were also red, as previously detailed by Stukeley.

In 1974 small samples were scraped from the carvings in the cave by Dr H. Cameron of Cambridge University and the Monumental Brass Society to see if any paint remained, and if so, could they be dated. Unfortunately, the control samples taken seemed to show the same elements found in the test ones, and no real conclusions could be found. One chemical element found that was of interest was cadmium sulphide, which could be used to produce yellow, though this method was not used in Europe before the date the cave was discovered, so this could have been a later addition to the cave. There were traces of lead found in all samples and it was suggested that this could have been from the exhaust fumes of the cars that used the road above the cave, via the grille vent in the pavement.

Maybe with better techniques that the 21st century can offer we may be able to take samples and determine the age of the paint that remains. Present day we can only see a pale orange tint above the carvings on the west wall. A colour that has not been mentioned by any of the early historians who visited the cave, but this may been red pigment that has now degraded. It has certainly been consistent with all accounts that the chalk, clunch bricks situated at the east shaft have always been painted red, and these were not sampled in 1974. If the composition of the paint could be determined it may provide important clues as to when the cave was being used.

However, it must be noted that at one point Joseph Beldam says of the carvings that ‘most if not all of them have been coloured, though perhaps at a later period’. Does this last comment suggest that some of the carvings were painted post discovery?

Another Royston Cave mystery we may not be able to solve!

The clunch bricks situated on the Eastern shaft, painted red. © Royston Cave

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References

Beamon, S.P. (1992). Royston Cave: Used By Saints or Sinners? Baldock: Cortney Publications.

Beldam, J. (1898). The Origin and Use of the Royston Cave. Fourth Edition. Royston: Warren Bros.

Taggert, E. (Dec 2022). Unearth the Colorful History of Paint: from Natural Pigments to Synthetic Hues. Website. May 2024.  <www.mymodernmet.com/history-of-paint/>