· Silica sand is the primary source of silicon dioxide that is essential in the manufacture of glass. To be suitable for producing glass, there must be a very high proportion of silica (above 95%) in the composition of the sand. That's why most sand deposits are not of sufficient purity for glassmaking.
Drury Quarry is one of the largest and most technically advanced quarries in New Zealand. It incorporates a quarry based pugmill for producing modified aggregates. A greywacke resource, Drury Quarry ranks amongst the biggest producers of aggregate in the Auckland region, supplying over a quarter of its requirements.