Month: October 2025

The Introduction to this Calendar can be found here. The Calendar features groups of beach stones I have collected recently, a different group each month. The stones are rough (un-polished) and usually wet, showing their colours and details. These 2026 Calendars are for sale, with postage within New Zealand included, for $35 non-rural, $40 rural. Two Calendars to the same address cost $60 non-rural, $65 rural. Three Calendars to the same address cost $85 non-rural, $90 rural. Email me at john.tumblestone@gmail.com.

The month of February features five banded argillite stones, four from Gemstone Beach and one (Stone Three) from Papatotara, a few kilometres further west. Argillite is a hardened mudstone – more details can be found in “M is for Mudstone from McCracken’s Rest”. Layers or bands of differently hued sediments are preserved in these stones. Generally, banded argillites come in green, gray, or brown, often with very dark or very light bands as well. Sometimes the bands seem to have a pottery glaze appearance, maybe due to extra time under heat and pressure.

Calendar Cover, 2026.

February.

February’s banded argillites.

Stone One (top row, left, in the Calendar) is a good example of maybe the most attractive form of banded argillite, with its semi-regular light and dark bands :

Stone One, February.

It is a small stone, found on Gemstone Beach on 23 August 2025, but I have found larger ones very similar in character, such as the one in “B is for Banded Argillite”.

In Stone Two a couple of the bands seem to have mixed, the band boundary having partially broken down. Maybe this happened when currents on the ocean floor, or a passing fish, disturbed the sediments. Stone Two was found on Gemstone Beach in March 2024:

Stone Two, February.

Stone Three has a similar disturbed band boundary as Stone Two:

Stone Three, February.

It was found on 15 August 2025 at Papatotara, about 15 kilometres west of Gemstone Beach along the Te Waewae Bay coast. A week earlier, I had picked up Stone Four on Gemstone Beach:

Stone Four, February.

Stone Five looks as if it has been affected by tectonic stress, with some of the bands broken up and dislodged:

Stone Five, February.

It is also a Gemstone Beach find, from early March 2025. Because of their original neat and regular banding, banded argillites provide very good displays of the effects of tectonic stress.

For March’s stones, see this Post.

The Introduction to this Calendar can be found here. The Calendar features groups of beach stones I have collected recently, a different group each month. The stones are rough (un-polished) and usually wet, showing their colours and details. These 2026 Calendars are for sale, with postage within New Zealand included, for $35 non-rural, $40 rural. Two Calendars to the same address cost $60 non-rural, $65 rural. Three Calendars to the same address cost $85 non-rural, $90 rural. Email me at john.tumblestone@gmail.com.

The month of January features five green-hued stones, all found on Gemstone Beach, Southland, in 2025. In New Zealand, we tend to associate green and stones with greenstone, especially pounamu or nephrite jade. However, the beaches I visit don’t have this stone. Nevertheless, I do find green stones, some of them quite intense in colour. For some information on the colour green in relation to stones, see “Gemstone Beach and its Stones: An Introduction for the Passing Motorist – Part Seven-A, Green Argillite Stones”. The following outlines the character and source of January’s five green stones. The photos used are the original ones used in the Calendar.

Calendar Cover, 2026.

January.

January’s green stones.

Stone One (top row, left, in the Calendar) is a strong green with angular patches of a speckled material. The patches seem to have a light green border around them:

Stone One, January.

I can’t decide what kind of stone this is. It could be a breccia, made up of fragments of the speckled material cemented together in the green mineral (the month of November features four breccia stones). Or it could be made up of the speckled material which has then been flooded with the green mineral that has invaded only part of the stone. The green mineral is likely to be epidote (see “E is for Epidote”). I found this stone in August 2025 during a three hour fossick on a cool Southland morning. This was the seventh visit I had made to Gemstone Beach that month. I also found Stone Three there that morning. For a good introduction to Gemstone Beach, see this Post, which describes the kilometre or so of the Te Waewae Bay coast that I usually walk to look for stones, and this Post, which describes the smaller area of Gemstone Beach in detail.

Stone Two (top row, right, in the Calendar) is also a Gemstone Beach find but from earlier in 2025, in March, picked up on the day of an earthquake. It is likely to be a mix of quartz and epidote:

Stone Two, January.

That there was an earthquake that day is appropriate as this stone is a tectonic breccia – tectonic stress has fragmented the lower left quadrant and then silica and epidote have filled the gaps.

I found Stone Three (bottom row, left, in the Calendar) the same day I found Stone One, on 12 August 2025. It looks to have a few large green spots in it:

Stone Three, January.

The large green spots could be rounded fragments of a green stone, cemented in white quartz material, which would make this a conglomerate. A conglomerate has rounded fragments in it while a breccia has angular fragments. However, there are a few smaller green fragments in the stone which are angular. An alternative identification is that the green features in the stone are crystals of some kind, again probably epidote. I am unsure.

Stone Four (bottom row, centre, in the Calendar) was found on Gemstone Beach in March 2025. It has a dash of iron oxide red mixed in with the epidote green, with a spot of purplish iron oxide in its lower right:

Stone Four, January.

Like Stone Two it is a tectonic breccia, having been fragmented by stress forces.

Stone Five (bottom row, right, in the Calendar) is the most intense green of the month’s stones. I found it the same day I found Stone Two:

Stone Five, January.

Among the features of this stone are small fragments of clear and milky quartz.

For February’s stones, see this Post.

Calendar Cover, 2026.

Scan of Calendar Cover.

Calendar 2024 #2 Cover

Cover of 2023 Calendar.

2022 Calendar Cover

2020 Stones Theme (Gemstone Beach on Cover again)

For the last few years, I have produced calendars on stone-related themes for family and friends, essentially an amateur effort to share some of the often-gorgeous beach stones I have found. I have made a few copies of the Calendars available for sale as well – at the end of this Post are price details for the 2026 Calendar. For recent past versions, see the 2023 Calendar, 2024 Calendar and 2025 Calendar.

The 2026 TumbleStone Calendar features groupings of beach stones I have collected during recent South Island fossicking trips. Each month features four, five or six photos of stones of a particular type. The stones are rough (unpolished), though they are quite smooth beach stones, and they are wet so that the details of their colours and patterns show clearly. Here are the stones on the Cover, one from each month in the Calendar:

A January stone.

A February stone.

A March stone.

An April stone.

A May stone.

A June stone.

A July stone.

An August stone.

A September stone.

An October stone.

A November stone.

A December stone.

In total, for the 12 months, there are 56 stones featured in the Calendar.

I use Diamond Photo, an Auckland-based company, to produce the Calendars. They provide a means online to place photos in a format for each month. There are a number of other companies with websites that do the same thing.

Diamond Photo home page. https://diamondphoto.co.nz

Diamond Photo “Calendars” page. https://diamondphoto.co.nz/collections/calendars

Diamond Photo “Wall Calendars” page. https://diamondphoto.co.nz/products/wall-calendar

Screenshot of cover in edit mode.

Screenshot of Cover in online review.

Screenshot of February photos in edit mode.

Screenshot of February in online review.

The printed product is very good but it is difficult initially to know how accurately it will reproduce what you see on your computer screen. Photos can turn out to be darker or lighter, for instance, and appropriate text size is hard to judge. I always get a draft of the Calendar sent to me to allow me to see how it turns out and to make any adjustments before finalising it, and I often do a second draft as well.

The Calendar photo page for each month is A4 size, with an A4 set of dates below that. Spiral binding keeps everything together. In the 2026 Calendar, January features five green-hued stones, February has five banded argillites, March presents six pink stones, and April has four poppy jaspers (photos of the final Calendar version below – they are not always accurate, the Calendar itself is generally clearer and the colour more balanced):

January.

January’s green stones.

February’s banded argillites.

March’s pink stones.

April’s poppy jaspers.

April.

Five differently coloured quartzites from Kakanui feature in May, June presents six black and white igneous stones, five trace fossil stones are in July, and August has six yellow stones:

May.

May’s Kakanui quartzites.

The black and white igneous stones of June.

July’s trace fossils in argillite.

The yellow stones of August.

August.

In September there are photos of five unidentified stones, October has five more Kakanui quartzites, November presents four breccia, and December features five hydrogrossular garnets:

September.

Some unidentified stones appear in September.

More quartzites from Kakanui in October.

November’s breccia.

December’s hydrogrossular garnets.

December.

The following Posts provide more details on each month’s stones: January, February, March, April, May, June, July, August,September, October, November and December.

These 2026 Calendars are for sale, with postage within New Zealand included, for $35 non-rural, $40 rural. Two Calendars to the same address cost $60 non-rural, $65 rural. Three Calendars to the same address cost $85 non-rural, $90 rural. Email me at john.tumblestone@gmail.com.