Archaeologists have found sherds from four small sphero-conical vessels in a destruction layer, dating between the 11th and 12th century CE, in Jerusalem, Israel. One of the sherds was from a stoneware sphero-conical vessel with very thick walls and no decoration; it may have held the chemical ingredients — including fatty acids and notable levels of mercury, sulfur, aluminum, potassium, magnesium, nitrates and phosphorous — of an explosive device.
“Ceramic vessels with conical bases and spheroidal bodies — so-called ‘sphero-conical vessels’ — have been found in large numbers in many varied archaeological contexts throughout the Middle East from the 9th to 15th century CE,” said Dr. Carney Matheson, a researcher at Griffith University, and colleagues.
“The diversity of manufacture, decoration, vessel morphology, and their broad distribution across the Middle East, from Egypt to Central Asia, suggests that the basic vessel design was used for a wide range of functions and contents.”
“Apart from their characteristic short neck, narrow opening, conical bases and spheroidal bodies, the size of these vessels varies from a few centimeters to over 20 cm in diameter with a wall thickness that varies from only a few millimeters to over 1.5 cm thick.”
“They have been manufactured using a wide range of firing temperatures from low temperature firing to a specialized very high temperature firing that produces stoneware.”
“Residue analysis has the potential to provide evidence that would allow us to characterize the contents of these vessels and enhance our understanding of luxury items, medicines, technology and trade in the medieval Middle East.”
In the research, Dr. Matheson and co-authors examined four sherds excavated from 11-12th century Mamluk contexts in the Armenian Garden, Jerusalem. The area includes the site of the Crusader royal palace.
According to the team, the vessels for each of the four sherds can be interpreted as either a multiple use vessel containing various chemicals or the residue from an explosive material; a container for medicinal or scented materials; a container for medicinal material and a container for oil.
“Our research has shown the diverse use of these unique ceramic vessels which include ancient explosive devices,” Dr. Matheson said.
“These vessels have been reported during the time of the Crusades as grenades thrown against Crusader strongholds producing loud noises and bright flashes of light.”
“Some researchers had proposed the vessels were used as grenades and held black powder, an explosive invented in ancient China and known to have been introduced into the Middle East and Europe by the 13th century.”
“It has been proposed that black powder may have been introduced to the Middle East earlier, as early as these vessels from the 9th-11th century.”
“However, this research has shown that it is not black powder and likely a locally invented explosive material.”
“We also revealed that some of these vessels have been sealed using resin,” he added.
“More research on these vessels and their explosive content will allow us to understand ancient explosive technology of the medieval period, and the history of explosive weapons in the Eastern Mediterranean.”
The team’s results appear in the journal PLoS ONE.
C.D. Matheson et al. 2022. Composition of trace residues from the contents of 11th-12th century sphero-conical vessels from Jerusalem. PLoS ONE 17 (4): e0267350; doi: 10.1371/journal.pone.0267350