The Tractatus de lapide philosophico is a treatise on the Philosoper's Stone, the legendary alchemic substance which was supposed to transform a base metal into a precious one, i.e. gold or silver. The treatise was attributed to the famous philosopher and theologian Thomas Aquinas (1225-1274), but intertextual relationships with other texts suggest a date of composition after 1351-52, well after his death. The attribution to Thomas Aquinas might have been suggested by the legend that ascribed the discovery of the Philosopher's Stone to Aquinas' teacher Albert the Great (1193-1280). The treatise is anonymous in the manuscript.

The text begins with the words Nunc vero de corporibus inferioribus tractandum est which correspond to the beginning of the second chapter. The first chapter is missing. The text ends with the words pondus aurei et surditatem et flectibilitatem. Amen. Finis.

A colophon (i.e. a short statement usually containing information about the scribe, and date and place of writing) which followed the text has been erased.