Elissa’s story has as its protagonist Calandrino, a Florentine painter and “simple, unconventional sort of fellow.” His friends include Bruno and Buffalmacco, other Florentine painters who are as “shrewd” and quick-witted as he is simple.
The Decameron wrings as much as it possibly can out of hapless, simple-minded Calandrino and his impish friends Bruno and Buffalmacco. Calandrino and Buffalmacco are both based on artists who were contemporaries (or near-contemporaries) of Giovanni Boccaccio.
Thanks to Calandrino’s reputation for gullibility, notorious trickster Maso del Saggio decides to play a prank on him. Finding him in a local church, Maso del Saggio places himself in earshot and loudly describes the properties of magical stones until he’s tempted Calandrino to join the conversation. Maso tells him that most magical stones can be found in Nomansland, where the mountains are made of Parmesan cheese and the streams flow with wine. Because Maso keeps a straight face, Calandrino believes everything he says. He asks if Florence has any magical stones, and Maso explains that there are two kinds: sandstone millwheels (which are costlier than emeralds in Nomansland) and heliotropes.
Unlike the first two tales of the day (and all of those on the previous day), the trick Maso del Saggio (also based on a well-known Florentine citizen and prankster) plays on Calandrino has no sexual motive. Instead, the trick (and the tale’s humor) are based in intelligence—or in Calandrino’s case, lack of both sophistication and common sense. The magical places Maso lists, like those in Friar Cipolla’s sermon in an earlier tale (VI, 10), only sound impressive. Calandrino’s inability to realize that they are nonsense names shows the depth of his ignorance and gullibility.
Maso del Saggio tells Calandrino that heliotropes, which are nearly black stones with the magical property of making someone invisible when he is out of sight, can be found near Florence. Calandrino searches all over the city to tell Buffalmacco and Bruno about the heliotropes, remembering hours later that they’re painting a nunnery. Finding them there, he explains the stones’ magical properties and his plan to make himself invisible to take coins from moneychangers. Bruno and Buffalmacco pretend to be impressed and suggest that they go rock hunting on Sunday morning. It will be easier to find black stones in the morning, before all the rocks are sun-dried and whitish. And fewer people will witness them on the weekend.
Maso del Saggio dangles what sounds like an enticing prospect in front of Calandrino, but the “magic” he describes is unprovable: if someone is only invisible when out of sight, how will he ever know? Calandrino’s difficulty in locating his friends (even though they are committed to be at the nunnery) is very funny, since it calls into question his ability to find a hidden, magical stone if he can’t even find his un-hidden friends.
The delay gives Bruno and Buffalmacco enough time to plan their own prank. On Sunday morning, they go with Calandrino to search just beyond the city walls. Calandrino picks up every black stone he sees, stuffing them into his clothes until he is “fully laden.” At this point, Bruno and Buffalmacco pretend that they can’t see him. They complain that he’s gone home without them while Calandrino, concluding that one of his many stones is magical, skips ahead of them. They throw stones which hit him, but he swallows his cries. Having previously bribed the customs guards to let Calandrino pass unremarked, they maintain the illusion that he’s invisible when they reenter Florence.
Calandrino’s friends encourage him to look even more the fool when they let him load up his clothes to bursting with rocks before they pretend that he’s found the magical heliotrope and become invisible. Their trick begins to seem more mean-spirited when they start to “randomly” hit him with rocks, but he demonstrates his commitment (if not intelligence) by holding his tongue.
But as Calandrino enters his house, Calandrino’s wife, Tessa, chides him for missing breakfast. Stunned that she can see him, he cries that she “ruined everything” and begins to mercilessly beat her. Bruno and Buffalmacco arrive shortly afterward to find Tessa cowering in the corner of a room strewn with black stones. When they chide him for allegedly abandoning them at the river, Calandrino protests that he found the heliotrope and turned invisible, returning to the city with neither they nor the customs guards noticing him. But then his “blasted devil” wife met him at the door and, because everything loses “virtue in the presence of a woman,” she broke the spell.
If the trick seemed harmless (if a bit mean-spirited) before, when Calandrino gets home, it has violent consequences. Although the trick was played on her husband, it’s Tessa who pays for it in the form of a violent beating, emphasizing the vulnerability of even innocent women to male violence. Calandrino’s assumption that his wife has ruined his magic stones is based in antifeminist fears that women were so sinful and corrupt that they ruined everything else around them by their very presence. His proverbial wisdom also carries a double entendre, suggesting that everyone is at risk of losing his virtue (sexual control) in the presence of a woman, because they are so very lustful.
Calandrino jumps up to resume beating Tessa, but Bruno and Buffalmacco restrain him. They say it’s his own fault for not telling her to stay away from him on the day he knew he was looking for the magic stone. They even suggest that, since he abandoned them at the river without sharing his discovery, God rewarded his treachery by allowing Tessa to ruin the magic. After reconciling him with his wife, they leave him brooding over his pile of useless stones.
Bruno and Buffalmacco neither own up to their trick nor express regret for the harm that Tessa has endured because of it, confirming her secondary and vulnerable position as a woman in a patriarchal culture (controlled by men). However, they do intervene enough to stop Calandrino from continuing. They suggest that his ill fortune ruined the spell (without fully absolving Tessa for being a woman and women for ruining things). Because he is gullible and prone to believe in magical or otherworldly explanations, he accepts their hypothesis.