Help finding Heart Crystals in Expert Mode

[Arthur]

I started a new character and world on Expert mode to play with a friend, but we're struggling to find more Heart Crystals. We've already dug all the way down to Hell, occasionally exploring caves along the way, as well as the jungle a bit, but we only found like... Six or so (enough to get us both 160 max HP). Is the Heart Crystal's spawn rate lower on Expert? Any tips for finding more? We managed to defeat Eye, but Brain is too hard for us with such low HP :p

[Thund3rStruck86]

use spellunker potions

[Hedning]

How common they are doesn't change depending on difficutly setting. Get some movement accessories, like hooks and boots, some shine and spelunker potions, and explore easier parts of the map, ie not the jungle or the underworld.