2506 Quartz (Excl. Natural Sands), Quartzite, Whether or not Roughly Trimmed or Merely Cut, by Sawing or Otherwise, Into Blocks or Slabs of a Square or Rectangular Shape

2506 (01/1988-..) Quartz (Excl. Natural Sands), Quartzite, Whether or not Roughly Trimmed or Merely Cut, by Sawing or Otherwise, Into Blocks or Slabs of a Square or Rectangular Shape 25061000 (01/1988-..) Quartz (Excl. Quartz Sands) 25062000 (01/2007-..) Quartzite, Merely Cut, by Sawing or Otherwise, in Blocks or Slabs of a Square or Rectangular Shape 25062100 (01/1988-12/2006) Crude or Roughly Trimmed Quartzite 25062900 (01/1988-12/2006) Quartzite, Merely Cut, by Sawing or Otherwise, in Blocks or Slabs of a Square or Rectangular Shape (Excl. Roughly Trimmed)