From their description it looks like they are similar to the crytal cluster. I haven't seen any combinations made with them though
Tired of your BB box components combining? I've found an easy way to manage your items so that you can stack infinitely many of them without them combining. If you wish to collect and stack every single componenent, you will require 3 showcases, however if you only use 1 item up or sell/swap it for others, you can make everything fit neatly into 2 showcases. Each row below lists the items contained in each showcase. The item to sell off are the floofs! FLOOF - SCIENCE, METAL, EGG - YARN, PAPER, SPROUTS, SWAG, DARKNESS - Any showcase: CRYSTAL