Answer:
Iām white; perfect for cutting & grinding. For most animals I am a useful tool.
The more of me there is the less you see.
To you, rude would I never be, though I flag my tongue for all to see. What am I?
I have six faces but not even one body connected 21 eyes in total but cannot see.
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.