ed and lucius (lucius who represents stedes sensitivities) aren't impressed.

it's not even the point of the trip, they just found it on accident.

and after ed thinking it's kinda cool, he fights a bug and has an emotional fit. but stede holds the little bug(heart) steady! ed checks it out, but doesn't get it back so that means stede is holding ed's little delicate sensitivities and his little heart (so tiny it can only fit one person inside it).

they move on and find the treasure they've been looking for, burried under the roots of jim's dead's family tree. it's just a rock :(

but ed takes it sees something more in it, he pours water on it (i think ed represents the sea/water so it's like he's literally pouring himself on his heart) and he sees and tells everyone there's something more to this rock. the old tree(stede and his family) has some fruit to give after all. a petrified orange.

(stede also represents the land so hes perhaps washing stede off his heart and washing him with his essence its the fruit of stedes land like stedes heart but only love and ed could figure out what it really is)

in spite fear, and anxiety stede's heart grew stronger. while the opposite effect took place with ed's heart, it probably grew weaker!

but stede doesn't want to give it to jim or anyone and he keeps it for himself, he won't give it to ed until s2.

Bear with me and my thoughts:

For the first time, the heart mattered in the killing of the judge in Will's case. The judge questioned Hannibal's testimony, claiming that he was biased. The judge ended up blindfolded, with a sword in one hand and a scale in the other, like Themis. Two things were placed on the scale: the brain and the heart. Although in reality the brain is heavier than the heart, by more than three times, here, somehow, it is the heart that prevails in the scale, and the brain is also in the shadow — this murder was not rational, but filled with emotions. Because… Hannibal really wanted to get Will out of prison, and on top of that, someone else started sending Will "Valentines" too. He couldn't accept it. He wanted to be the only person able to help Will.

The second time the heart is important is in the case of a tableau with poisoned flowers placed in place of pulled out organs. Recreating this crime as the perpetrator (Hannibal), Will arranges the flowers that are supposed to be the heart in the right place and only then does it begin to beat.

The last time Hannibal gives Will his heart, it's a valentine from a broken heart written on a broken man. Hannibal put it on a tripod made of swords. This arrangement of these items in the tarot means forgiveness. Hannibal forgave him for his betrayal. The heart was made of Anthony — Saint Anthony is the patron saint of what is lost, Hannibal's prayer for Will to return to him (@t3acupz thank you for pointing the said saint). And this heart comes alive. Do you know when? When Will touches it.