Month: February 2022

February-March 2022 Fossicking Trip: Stone of the Day #18, Gemstone Beach Green “Finger”

I am being much more selective during my fossicks on Gemstone Beach now as this was my ninth visit there this trip. I have accumulated quite a few finds to take home with me back to Whanganui – that trip north starts in three days’ time. I collected about 80 to 90 stones today, some of them quite small, which is less than half of what I have tended to collect in previous days. Today’s Stone of the Day is another Gemstone Beach green – it looks kind of like argillite, especially in colour, but its structure close-up looks more like quartzite:

Stone of the Day #18

The stone is 5 cms long and is (roughly) finger-shaped:

Other side of Stone #18.

On my way back to the carpark this afternoon, a woman who was also fossicking generously gave me a handful of the hydrogrossular garnets she had found – she was doing much better at it than I!

Among this handful of hydrogrossular garnets are the half-dozen I was gifted by a fellow fossicker.
People looking for stones in front of the carpark at Gemstone Beach. The sweeping curve of the Te Waewae Bay coast is apparent.

Six of my other finds today:

The first Post in this Series is here. The Index to all the Posts in the Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #17, Small Gemstone Beach Amygdaloidal Stone

I arrived at Gemstone Beach just an hour after high tide today. This meant that the waves were wetting stones much further up the beach than the last few times I visited. Consequently, many more stones were on display for the fossicker. It was difficult to decide on today’s Stone of the Day as more than a handful of the ones I found are probably worthy. I chose this small amygdaloidal stone, 3.5 cms long and 3 cms wide:

Stone of t.he Day #17

I found a few amygdaloidal stones today, of various sizes and kinds and colours. This one stood out because of the tiny size and high density of most of the amygdales.

The other side of Stone #17.

As today was Sunday and the sun was shining brightly (though the temperature could have been warmer), there were more people than usual on Gemstone Beach. At the start of my fossick, there were even a few who had forded the Taunoa Stream and had made their way along the beach. Most stopped after about 300 metres, and for most of the rest of my time there, I was the only one on the far side of the Stream.

People ahead of me on Gemstone Beach after I had crossed the Taunoa Stream.
Gemstone Beach stones.
Gemstone Beach stones.
Gemstone Beach, right near the carpark, on a weekend day in summer.

Other candidates for Stone of the Day today included these six:

The first Post in this Series is here. The Index to all the Posts in the Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #16, Another Slope Point Rhyolite

Today, Saturday 26 February, I made another visit to Slope Point. This was my fourth, and last, visit here this trip, arriving mid-afternoon. Low tide was at 6 pm and it is best to fossick at Slope Point during the last couple of hours of the outgoing tide – the sea can be wild here, with nothing but ocean to the south until you get to Antarctica. I have now been able to collect an interesting set of Slope Point stones to tumble polish over the next few months. Today’s stone is a medium-sized reddish rhyolite, 6 cms wide at its widest, 4.5 cms high and 2.5 cms at its base:

Stone #16.

Being this kind of volcanic stone, it is starting out as not very smooth, with small holes and furrows, but its interesting character means it is well worth trying to smooth and polish in a tumbler.

Other side of Stone #16.

I was in the company again of local fossicker Oliver Simpson.

Oliver on the Slope Point beach, wave breaking in background.
Looking in the other direction.

Three small rhyolite stones I found today:

Three non-rhyolite stones I collected, the first being petrified wood, I believe:

Highly likely to be petrified wood – the stone is dry in this photo.
Small very smooth stone.
Amygdaloidal stone.

The last five stones from today, all being volcanic in origin, with most (if not all) being rhyolites:

Light-coloured rhyolite stone.

The first Post in this Series is here. The Index to all the Posts in the Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #15, Hydrogrossular Garnet from Gemstone Beach

My fossick today on Gemstone Beach resulted in many more hydrogrossular garnets being found than on any of my previous visits this month. I was on the beach at a higher tide level, starting just 90 minutes after high tide. This meant I was able to see many more wet stones than before because the waves were running higher up the beach – including more hydrogrossular garnets.

I have learned which stones are hydrogrossular garnets from talking to other fossickers I’ve met on Gemstone Beach over the past five years, from seeing specimens in museums and private collections, from members of Facebook Rockhound Groups, and from various published and online sources (e.g. page 9 of Jocelyn Thornton’s “Gemstones”). However, stone identification in general is often debatable (is a stone a jasper or a quartzite?) and even local knowledge can be fallible. This Post represents the current state of my knowledge of what is or is not a hydrogrossular garnet (or what stone may incorporate some hydrogrossular garnet within it).

This Post refers to ten hydrogrossular garnets, labeled from “a” to “j” so you can locate them in the following photo of most of the garnets I collected today. Hydrogrossular garnets come in a range of types and you can find them in various shapes and sizes:

Most of the hydrogrossular garnets I collected today, arranged by size. $2 and $1 coins for scale.
Stones a to j are included in this Post.

Today’s Stone of the Day is a small blue hydrogrossular garnet (labelled “a” above):

Stone #15.

This type is not translucent as many other types can be – I refer to it as a “porcelain-type” because of its cool feel and very fine structure. It stands in contrast to the likes of the next hydrogrossular garnet, one of the rich brown types (included below are photos with a torch behind the stone):

With a torch behind it.

A tumble polished brown hydrogrossular garnet similar to the one above features in this Post. The next four hydrogrossular garnets illustrate part of the range of types to be found on Gemstone Beach and further northwest along the shore of Te Waewae Bay:

The next four are either relatively translucent or too small for close-up photos to be very revealing:

It was cloudy for the first half of my fossick but the sun shone brightly during the second half.

Gemstone Beach stones.
A cloudy morning.
Paradise shelducks high atop the cliff at the back of Gemstone Beach.
Gemstone Beach stones.
The Taunoa Stream, not far from the carpark.

I also found a few other stones worth collecting:

Unusual colour trace fossils.
I suspect this is a trace fossil stone – it has bumps which could be the traces.

The first Post in this Series is here. The Index to all the Posts in the Series is here.

Index to February-March 2022 Fossicking Trip: Stone of the Day

For four weeks in February-March 2022, I travelled by car from my home in Whanganui to the south of the South Island. I visited a number of beaches during this time, fossicking for stones to take home to tumble polish. I posted a Stone of the Day each day, usually a stone found that day. All the Posts also include other stones found during the trip. This Index allows you to click on a link to be taken to the relevant Post. The photos give you an idea of each Stone.

Stone #1 – Birdlings Flat Banded Agate

Stone #2 – Kaitorete Spit Quartzite(?)

Stone #3 – Timaru Beach Stone

Stone #4 – Kakanui Yellow Quartzite

Stone #5 – Kakanui Clear-Veined Stone

Stone #6 – Unknown Grey Slope Point Stone

Stone #7 – Jasper(?) from Gemstone Beach

Stone #8 – Gemstone Beach Red Stone With Orange Shapes

Stone #9 – Small Brecciated(?) Slope Point Stone

Stone #10 – Gemstone Beach Green

Stone #11 – Another Gemstone Beach Green

Stone #12 – A Slope Point Rhyolite

Stone #13 – A Gemstone Beach Jasper

Stone #14 – A Different Gemstone Beach Jasper

Stone #15 – Hydrogrossular Garnet from Gemstone Beach

Stone #16 – Another Slope Point Rhyolite

Stone #17 -Small Gemstone Beach Amygdaloidal Stone

Stone #18 – Gemstone Beach Green “Finger”

Stone #19 -Big Gemstone Beach Hydrogrossular Garnet

Stone #20 – Colourful Gemstone Beach Amygdaloidal Stone

Stone 21 – A Gorgeous Green from Gemstone Beach

Stone 22 – Small Dark Kakanui Agate

Stone 23 – Small Kakanui Hematite Jasper

Stone 24 – Kakanui Multi-Coloured Quartzite

Stone 25 -Small Kakanui Yellow Quartzite With Red Markings

Slope Point.
Ward Beach.
Seadown Beach, Kakanui.
Timaru.
Kakanui.
Slope Point.

Stone 26 – Quartz-Veined Quartzite(?) from Timaru

Stone 27 – Ward Beach Agate

February-March 2022 Fossicking Trip: Stone of the Day #14, A Different Gemstone Beach Jasper

Today was my sixth visit so far to Gemstone Beach during this trip. Another sunny day with practically no wind meant I spent another very pleasant three hours on the beach. Stone #14 is a jasper found when I was about halfway back to the carpark. It immediately commanded my attention with its bright red speckles:

Stone #14.

The stone is not a perfect one for tumbling, having some small holes and being convex on one side and concave on the 0ther. It is 5 cms long and 4 cms wide, 0.5 cm thick at one end and 1.5 cms thick at the other end, big enough to allow some shaping while tumbling.

Other side of Stone #14.

That makes it three Gemstone Beach jaspers that have featured as Stones of the Day in this Series, all three quite different in character:

Gemstone Beach seemed to have a bit more sand on it today as I made my way northwest along it. I suspect it’s not because the stones have been transported elsewhere by the waves but mainly that they lie buried under the sand. There were plenty of drifts of stones to investigate as well as the banks of stones towards the northwest.

Patches of sand and drifts of stones on Gemstone Beach. Looking southeast towards the carpark.
Gemstone Beach.

The stones I have selected to include in today’s Post illustrate the diversity to be found on Gemstone Beach:

Some of the stones are quite small, between 1 cm and 2 cms long:

Pink thulite stone.
Quartz type.
Small unusual coloured trace fossil stone.

And the final three today:

Could be argillite.

The first Post in this Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #13, A Gemstone Beach Jasper

I spent nearly four hours on Gemstone Beach today, most of it as the tide was retreating. Bright sunlight persisted throughout this period. The Stone of the Day looks like a light-coloured jasper to me, being 3.5 cms long and 2.5 cms wide:

Stone of the Day #13.
Other side of Stone #13.

There were a number of people on the beach again today. As usual, most of them stuck fairly close to the carpark, with only a minority wading the Taunoa Stream and less than a handful venturing further. Down the beach, close to the Waimeamea River, I spoke briefly to one couple from Whangarei, giving them a small hydrogrossular garnet I found.

Today the Waimeamea River was not flowing in a channel across the beach to the sea, as it had been doing the last couple of times I had visited. The high tide had thrown up enough stones to block its outlet. This increased the number of water seepages flowing under the stones in front of the lagoon, increasing the area of wet stones that could be searched. Some of the seepages were strong enough to cause scouring:

The southern end of the Waimeamea River lagoon, where yesterday it folowed out across the beach to the sea.
Scouring by seepages of water from the lagoon.
Water flowing from under the stones near the lagoon.

Other stones I collected today included a number of black and white ones:

Light coloured stones also feature today:

Small hydrogrossular garnet with a blush of blue.
Quartzite.
A kind of quartz??
Perhaps a kind of argillite??
Trace fossil stone, argillite.

The first Post in this Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #12, A Slope Point Rhyolite

Today I took another trip to Slope Point. I met up with a local fossicker, Mary, a member of the “New Zealand Lapidary, Rocks, Minerals, Fossils” Facebook Group, and we made our way to a beach known as Thunder Beach. We spent two hours there and collected a good bunch of stones. Today’s Stone of the Day is an interesting rhyolite:

Stone of the Day #12.
Other side of Stone #12.

It was a wet day but only light rain hit the beach from time to time, nicely wetting the stones for us to see.

Mary on Thunder Beach.
The cliff at the north end of the beach.
Slope Point beach stones.

Among the other stones I found today were these five, most of which are rhyolites, I think:

I also found one nice light-coloured petrified wood stone plus two interesting stones with green in them:

Thank you to Mary for her company and hospitality!

The next Post in the Series, on Stone #13, another Gemstone Beach one, is here. The first Post in this Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #11, Another Gemstone Beach Green

I arrived at Gemstone Beach this morning about an hour before low tide, leaving three hours later. Nice sunny weather meant conditions were great for a leisurely fossick. Mostly green stones feature in today’s Post, with the Stone of the day being a light pistachio green amalgam of fragments and shapes:

Stone of the Day #11.

The other side:

The other side of Stone #11.

Despite today being a Monday, there were still a number of people on the beach. Two of them even followed me a few hundred metres northwestwards, although we were well separated.

At 12.30 pm, when I left the beach.
At 9.30 am, when I arrived.
Three of us moved along the beach, well separated.
Seepages of water from the cliffs and Waimeamea River lagoon sometimes flow across the beach, making stones easier to spot.
Two shags flying by.

Now for some other green stones I found today:

The final four includes an amygdaloidal stone – a volcanic stone with small holes that have been infilled by a mineral left behind by water flowing through them:

Amygdaloidal stone – small holes in a volcanic stone infilled with a mineral.

The next Post in the Series, on Stone #12, a Slope Point rhyolite, is here. The first Post in this Series is here.

February-March 2022 Fossicking Trip: Stone of the Day #10, Gemstone Beach Green

Back to Gemstone Beach on Te Waewae Bay today. A 3 1/2 hour fossick took me a couple of kilometres along the beach, finding a range of stones for tumble polishing. Today’s featured stone is green, perhaps brecciated, with interesting “inclusions”:

Stone #10.
Other side of Stone #10.

Today being Sunday, there were more people on the beach than on a week day:

A few hundred metres along the beach, looking northwest.
On my return to the carpark about 1 pm, there were quite a few people near there.

I had collected a medium amount of stones for me, my backpack was not too heavy so I could enjoy the walk back. Three of the best from the rest of my stones:

Small quartzite.
Jasper.
Green quartzite.

Four more selected for their interest:

Thulite.

I found a few trace fossil stones with well-defined markings. They ranged in size from small to large-medium. Here are three I put in my bag, the largest being just a little too big to tumble but a fine example, covered in traces:

The next Post in the Series, on Stone #11, another Gemstone Beach green, is here. The first Post in this Series is here.