buhrstone, also burrstone /bûrˈstōn/

1. A variety of quartz, containing many small empty cells, which give it a roughness of surface particularly adapted for millstones
2. A millstone made of this

• tridominium
• tridominiums
• triduan
• triduum
• triduums
• tridymite
• tridymites
• trie
• triecious
• tried
• triene
• trienes
• triennia
• triennial
• triennially
• triennials
• triennium
• trienniums
• trier
• trierarch
• trierarchal
• trierarchies
• trierarchs
• trierarchy
• triers