Chrissy and I arrived at Gemstone Beach at 12.15 pm, 90 minutes before low tide. That gave us enough time to walk down the beach a fair distance and get back well before the tide came in. At high tide, the waves come right up to the foot of the cliffs which back the beach. Fossickers must make sure they avoid this danger. The temperature upon our arrival was only nine degrees but it was sunny and there was no wind, leading to a comfortable afternoon. We reached the Waimeamea River Lagoon just as the tide turned.
Near the Lagoon, as we were walking westwards, we met Jason, a fellow member of the Southland Geological and Lapidary Club, who was walking eastwards. We enjoyed a good chat and sharing of finds before parting.
Chrissy and I left the beach at 3.40 pm after a productive three and a half hours fossick. Just after arriving, we had spotted a horse and rider emerging from the slightly misty distance (see photos below). Horses appear sometimes on the beach- see for instance “Fossicking with Oliver, Te Waewae Bay, Sunday 26 March 2023” and “Forty-Three Finds and Four Horses on Gemstone Beach, Wednesday 5 March 2025”. Then, as we were getting close to the carpark at the end, an aircraft flew overhead, landing on the beach halfway between us and Monkey Island – the first time I had seen this happen!
I collected around 90 stones this afternoon, 16 of which are featured below. The first is one of my most intriguing finds, a melange of elements with a bright red mineral cloud on one side, probably iron oxide:
Next, a thulite stone with some bright pink patches:
A variety of types of stones with thulite in them can be found on Gemstone Beach. The pink can be bright and intense or it can be quite pale. Thulite is the national gemstone of Norway where it was first discovered in 1820. It is the pink to reddish variety of the mineral zoisite. As Minerals.net reports, “The color of thulite is caused by the element manganese in its composition. Thulite often occurs associated with quartz, and is sometimes mottled with streaks or spots of white quartz.”
I found a small poppy hematite jasper, a red type of orbicular jasper. It has a thin white vein and there’s also some tiny patches of a white mineral on one side:
Orbicular jaspers form due to the presence of minerals which crystallise in concentric layers around a central point, giving rise to orb-like structures. The orbs can be tiny or a bit larger. I found a very rare white orbed jasper during the final fossick of my March trip this year which has much smaller orbs than this find.
The following small stone caught my attention because of the dark blue areas on it. It has some great intense green epidote in it, and some white quartz, but the blue is more unusual:
I started spotting some hydrogrossular garnets today after not seeing them during the first two fossicks on Gemstone Beach this month. Of the two largest, one was a smoky brown colour, the other having a bright orange/yellow mineral in it:
Hydrogrossular is a massive form of garnet rather than a crystal form. It was first identified by a New Zealander, Colin Hutton, in the 1940s. He analysed some stones from Nelson, the other main area than Gemstone Beach that hydrogrossular can be found in this country. Hydrogrossular garnet is one of 13 minerals first described from New Zealand and accepted as valid by the International Mineralogical Association. For further information, see my 2023 Post “First Identified in New Zealand in 1943 – Revisiting the Hydrogrossular Garnets of Gemstone Beach”.
The next find is a grey mudstone, probably argillite, with very interesting nodules and swirls:
I also found a very small light grey banded argillite with find bands – it has a slightly glazed appearance, probably from being subject to a bit more pressure and heat during formation:
The next find is a darker grey in areas, and the swirls at the top caught my eye on the beach. However, looking at the photographs of it, my attention moved to the textured area of crystals at the bottom:
Another textured find, a stone packed with tiny features, many of them crystals, I think:
In my as-yet-unfinished Series “Gemstone Beach And Its Stones: An Introduction For The Passing Motorist”, I have a section on stones with opaque white crystals – see Stones W43 to W63 in this Post. Since then, I’m always on the look-out for good specimens reflecting the range of types. I found these two today:
The second of these two in particular interests me – the white in it is quite intense, and the close-up photos show that the crystals, if that is what they are, have tiny grey veins in them, maybe the result of brecciation. I have a suspicion the white material is hydrogrossular garnet.
Finally, I continue to find great specimens of trace fossils in argillite. Here are four. The first is very rare, the clearly-defined traces being an interesting mix of dark and light hues in a black stone. The second has a much more subtle and faint trace. The third and fourth are good examples of types often present on Gemstone Beach.
Trace fossils are called “ichnofossils”. This term is derived from the Greek word “ichnites” meaning “footprint”. A trace is a fossil of an animal’s activity, such as movement and burrowing, not of the animal itself. More information can be found in the Post “The Tattooed Rock, The Trace Fossils…” Revisiting Gemstone Beach’s Trace Fossil Stones”.
The next Post in this Series is called “A Simple Song, A Simple Stone”, covering another fossick at Gemstone Beach. An Index to the Series is here.
It was a great day for spotting unusual-ness on the beach! That black trace fossil stone is super gorgeous. I’d have kept that if I’d seen it! 🤣