An emissary from Prester John arrives at the court of a Western potentate to explain the difference of precious stones already possessed, only to vanish with the stones elucidating their virtues. But the Italian story is from its outset a moral tale: ‘the form and intent of the mission was double: a desire to put to the test whether the emperor was learned in speech and in deeds.’ Having received the three stones, the emperor is supposed to indicate ‘what is the best thing in the world.’ The emperor, however, fails to inquire about the stones’ virtues, choosing to praise their beauty instead. The emperor concludes, somewhat ironically given the great opulence of his own court, that the best thing in the world is misura (moderation; the golden mean). After hearing report of the emperor’s words, Presto Giovanni judges the emperor ‘very wise in words, but not in deed, in as much as he had not asked about the virtue of such precious stones.’ Prester John then dispatches his jeweler (lapidaro) to retrieve the stones. Once the jeweler holds all the stones, he becomes invisible, returns to India, and presents the stones to Prester John ‘con grande allegrezza’ [with great happiness]” (p. 265).
