A new analysis of residues inside ancient 11th-12th century ceramic vessels in Jerusalem has revealed that they could have been used as hand grenades.
Previous research on the various sphero-conical vessels, found in museums around the world, had determined that they were used for a variety of purposes, such as containers for drinking beer, for mercury, for oil, and for medicine.
This latest research, led by Griffith University Associate Professor Carney Matheson, confirmed that some containers did indeed contain oils and medicines, and that some contained scented oils, consistent with other recent research on the use of the containers. /P> 
However, his findings also revealed that some of the vessels contained a flammable and probably explosive material indicating that they may have been used as ancient hand grenades.
Professor Matheson said the explosive material he analyzed inside the pots suggested there may be an ancient explosive developed locally. This research has shown the diverse use of these unique ceramic vessels including ancient explosive devices . These vessels are reported to have been thrown during the time of the Crusades as grenades at Crusader strongholds, producing loud noises and bright flashes of light .
Some researchers had proposed that the containers were used as grenades and contained black powder, an explosive invented in ancient China and known to have been introduced to the Middle East and Europe in the 13th century. It has been proposed that black powder may have been introduced to the Middle East earlier, as early as in these 9th to 11th century vessels . However, this investigation has shown that this is not black powder and is most likely a locally invented explosive material .
Professor Matheson said the investigation also revealed that some of these vessels had been sealed with resin. Further research on these vessels and their explosive content will allow us to understand the ancient explosive technology of the medieval period and the history of explosive weapons in the eastern Mediterranean .