You must have STREET SIGN and YELLOW BLOCK to make GEM SIGN. GEM SIGN is in signs category. Lunch brake plant. Not for speed eaters though. Breaking GEM SIGN gives you 5 experinece points per tree and block you brake. Currently we do not yet have knowledge about the durability of GEM SIGN. Oops, there is no entry in the database about seedratio. If you know something, please share. There is no data about gemratio. Currently we do not yet have knowledge about the blockratio of GEM SIGN.