Based on 'Rock glazes of NZ' Minna Bondy
Sample 86. Waimea River Sand
Some Quartz and Feldspar and also fragments of not well-preserved serpentine-like material, probably derived from ultra-basic rocks close to Nelson.
26. Waimea River Sand
This is the first blog that I have written after the testing process, so from now on I will include the results with the blogs along with the location and recipe. The previous blogs will be updated to include this information as I photograph the samples.
One thing I have learnt on this journey is just how many of our New Zealand rivers are used for commercial purposes. Aside from irrigation, river beds are also used for the extraction of gravel and leases provide an annual income for the district councils for works on and around rivers.
The Waimea River proved to be the hardest material to grind, the gravel had very little sand and failed to grind to a sufficient quantity. If I were to source this again I would try to access a point on the river that was less gravel and more silt, or sieve it onsite to filter out the chunky gravel.