When I arrived at Gemstone Beach for a solo fossick at 10am, there was a lot of fog along the coast, and the temperature was 12 degrees. That eventually lifted after about 45 minutes. I spent two and three-quarter hours on the beach, by which time the sun had raised the temperature to 17 degrees.
I chatted with a number of people picking up stones – some were from overseas and some were locals. They included a young couple who live in Wellington though they come from Scotland, an older couple from Cromwell, and two women from the United States, friends of Chrissy’s. Sometimes they showed me their stones and I talked about their identification, and sometimes they asked what I had found. I probably talked to eight of the 12 people there. The tide was low this morning and there was still a lot of sand on the beach. Just over the Taunoa Stream was a large patch of stones that people tended to spend time at. I walked down to the Waimeamea River which has been blocked from running to the sea – the waves had piled up stones there. Some seepages had formed as the water made it way in places through the stones.
Fourteen of my finds are featured below. The first is the largest hydrogrossular garnet I have found so far on this trip – these have not been showing up at all except for the very occasional quite small one. I found this large bashed-about garnet down near the Waimeamea River:
My most spectacular find this morning is another of those small jaspers that come to life with close-up photography. It proved difficult to get very clear images but the following give some idea of the amazing world in there:
It almost looks as if a tiny pen has made a tracery of lines and filled in patches – and the small white areas are attention-grabbing.
Next is another small red jasper (I found a couple more as well). In this one, the tiny white circular patch just above centre caught my eye on the beach – but the photos reveal a lot more:
Here are three argillite stones with trace fossils in them, illustrating the diversity that can be found on this beach:
An amygdaloidal stone with some bright red amygdales:
Amygdaloidal stones are also known locally as volcanic bubble-infilled stones. They originate in molten magma which may contain dissolved gas that forms bubbles in the rock. These tiny bubble holes then fill with mineral-rich fluids which leave behind deposits of minerals such as quartz, chalcedony, calcite and zeolites. The resultant “spots” are called “amygdales” (also “amygdules”), coming from the Latin and Greek words for almond, reflecting the almond-shape of many such in-filled holes. However, amygdales can also be round and some can be irregular shapes. Further Gemstone Beach amygdaloidal stones can be seen in this Post, Section 4, Stones W30 to W42.
A small stone with a very busy composition – it looks like a polymictic breccia, a stone full of tiny angular fragments from a variety of sources, some of which look to be mudstone/argillite:
Next are five of this afternoon’s finds where the predominant colour is green, most often due to the presence of epidote – the first two and fourth are probably quartzite, some have quartz veins or patches, and some brecciation can be seen at times:
Finally a grey stone with tiny black and white crystals and/or fragments:
A severe storm is heading our way, bringing heavy rain and strong winds over the next few days. Some parts of New Zealand are under a Red Warning – significant impacts and disruption are expected. The stormy waves will stir the beach stones up (and move sand around) but may make fossicking uncomfortable.
“There’s A Storm A-Coming”
by Richard Hawley
There’s a storm a-coming, you’d better run
There’s a storm coming, goodbye to the sun
There’s a storm a-coming, you’d better run boy run
You’d better run
There’s a ship that’s sailing out in the night
There’s a heart that’s breaking, I think it’s mine
There’s a storm a-coming, you’d better run boy run
You’d better run
Every little part of you is a miracle of molecules
Every little thing you do so sad, in the end
Oh, in the end
There’s a ship that’s sailing out in the night
There’s a heart that’s breaking – I think it’s mine
There’s a storm a-coming, you’d better run boy run
You’d better run
The next Post in this Series is my fourth and final visit to Gemstone Beach on this trip. An Index to the Series is here.
