Minecraft wiki entry for Defeating_a_Nether_fortress, associated text: Your bow is useless without arrows. If you haven't picked up some glowstone yet or find some within easy reach, go ahead and mine it because it will be useful for brewing, powerful lighting, and to make spectral arrows.‌[Java Edition only] Four glowstone dust and an arrow makes two spectral arrows. A spectral arrow, when it hits an entity, makes it glow for a brief time which can help with visibility. If you are low on arrows, using spectral arrows can double your arrow count.