You can make GEM SIGN by combining STREET SIGN and YELLOW BLOCK. You can find this item in signs category. Growing GEM SIGN takes 0d 02h 44m 51s. Breaking GEM SIGN gives you 5 experinece points per tree and block you brake. Hitting it will break it but you need to count the hits yourself. You get at least 1 seed back (maybe more!) from splicing GEM SIGN. Will you strike it rich? You just have to count the gems yourself. Massproducing GEM SIGN can be tricky. You will find out after you have harvested a few.