It is commonly claimed the burn marks from the 1532 fire was caused by molten silver.
The shroud was damaged in a fire in 1532 in the chapel in Chambéry, France. There are some burn holes and scorched areas down both sides of the linen, caused by contact with molten silver during the fire that burned through it in places while it was folded.
https://en.wikipedia.org/wiki/Shroud_of_Turin
However, this is not likely to be the case. The burn marks are triangular shaped. Molten silver should cause round shapes, not triangular shapes. Also, the melting temperature of silver is 961.78 °C (1763.2 °F) and the ignition temperature of linen is 310 °C. So, the cloth should’ve burst into flames well before silver started to melt.
The shroud was folded in the following configuration in the reliquary:
We conclude that at Chambéry the Shroud was
thus folded up and that the Shroud pack length
was about 75 cm and its width about 29 cm, with
four layers of four thicknesses on one side and
eight layers of four thicknesses on the other side.The RH side of the Shroud pack thus folded up includes a total of 16 layers and its LH side a
total of 32 layers, with once more a complete and precise accordance between its various
parts.
The size of the large triangle is 10 x 18 cm, which is much too large for silver droppings to form.
The cloth damage does not look like silver dropping down, but more like the end of a plank that fell down.
The real fire experiments, as well as the data processing
simulations we carried out, demonstrate the possible
slanting fall of a burning metal strip or lid part.
https://www.shroud.com/pdfs/aldo3.pdf
Analysis of the large water stains also show they are not related to the 1532 fire. The water stain fold patterns do not match the burn mark fold patterns.
the large water stains we mentioned first of all do not have any connection whatsoever with the folding system we have just described.Indeed, after drawing these large water stains on
transparencies which we folded according to the
system just descr ibed, we observed that there
wasn’t any accordance whatsoever. Therefore,
we consider that these large stains cannot be
considered part of the same incident.
https://www.shroud.com/pdfs/aldo3.pdf
Ian Wilson provides this account of how the shroud was saved.
On the night of December 4, 1532, fire broke out in the Sainte Chapelle, Chambéry, where the Shroud was then kept. Flames spread quickly through the chapel, engulfing rich furnishings and hangings in their path. A beautiful stained-glass window of the Shroud, completed only ten years earlier, melted in the heat, and the cloth itself was only saved by the quick intervention of one of the duke of Savoy’s counselors, Philip Lambert, and two Franciscan priests. Together they managed to carry the already burning casket out of the building. But they were too late to prevent a drop of molten silver falling onto the linen inside. This set fire to one edge, scorching all forty-eight folds before the fire could be doused with water. When the reliquary was opened up, the Shroud presented a sorry picture of holes, scorch marks, and stains left by the water. Yet, seemingly miraculously, the image itself had scarcely been touched.
http://theshroudofturin.blogspot.com/20 … mages.html
However, this account doesn’t line up with the evidence. A better explanation is the triangular burn marks are caused by the collapse of the reliquary the shroud was stored in while it was being rescued.
The reliquary was sealed by four locks that required four different keys. When the reliquary was pulled from the 1532 fire, since they could not open the locks, they had to axe their way through the reliquary to open it. Most likely, this caused part of the top of the reliquary to collapse and formed the large triangular burn mark. The temperature inside the box never got to the ignition temperature of linen and likewise it never got to the temperature for silver to melt. However, the fire did cause the silver box to heat to a sufficient temperature that when it collapsed, it burned the cloth.
https://debatingchristianity.com/forum/viewtopic.php?p=1126182#p1126182