Board Thread:News and Announcements/@comment-67.140.221.67-20160930231239/@comment-30096930-20161003022426

73.Anon.52 wrote: glass is made using silicates(AKA sand).... provided cinder used actual sand in addition to fire dust it is perfectly possible for orange dust to still make glass weapons and behave as lava even if all it does is fire.... so yes clarification helps.

Lava specifically makes black glass (obsidian) though which sand is not needed.