You must have ORANGE WALLPAPER and BLACKROCK WALL to make GOTHIC BUILDING. GOTHIC BUILDING is in bouncing category. Using growspray would be madness, better get a time machine. Breaking this block will give you 18 experience points. GOTHIC BUILDING can be broken. Seed mathematics is very complicated, but you should get at least 1 seed back from splicing GOTHIC BUILDING. Gemratio of GOTHIC BUILDING is a mystery. Maybe you can check the wiki for <a href="https://growtopia.fandom.com/wiki/Gothic_Building">gothic building</a> Will you get enough blocks to build something? You just have to find out yourself.