Using flint to create sintered blocks and crying obsidian

Flint could be used to create crying obsidian, first the player would use 9 flint to create a block of black gravel which then could be turned into a sintered flint block by putting it in a furnace or next to lava, much like how concrete powder is turned into concrete when it touches water. The black gravel could also drop 9 flint when destroyed without silk touch

The sintered flint block could then be mixed with obsidian like course dirt to create the new crying obsidian :)