So, from using this I've managed to find Kraken's Heart, Industrial Heart and Inky Sapphire (although my chemistry discoveries list shows it as Kraken's Sapphire). There's still a big gap in between the hearts and the sapphire, though. I'm fairly certain there's more that can be made from the Kraken's Heart, since I didn't get a chance to go through many possibilities before making the Industrial Heart. Unfortunately I ran out of sludge hearts, and I've forgotten which path I needed to take to get more, so I ran out of energy before getting another for further experimentation.
Kraken Ink / Discussion
This is the discussion related to the wiki page Kraken Ink.