Splice GRIMSTONE and BROWN BLOCK to make DARK BROWN BLOCK. DARK BROWN BLOCK is in color blocks category. DARK BROWN BLOCK is good to plant before you head to some parkours. Received experience is a mystery. Keep an eye out for the exp counter. Hitting it will break it but you need to count the hits yourself. You get at least 1 seed back (maybe more!) from splicing DARK BROWN BLOCK. Gemratio of DARK BROWN BLOCK is a mystery. Maybe you can check the wiki for <a href="https://growtopia.fandom.com/wiki/Dark_Brown_Block">dark brown block</a> Massproducing DARK BROWN BLOCK can be tricky. You will find out after you have harvested a few.