Photo-Book “The Trace Fossil Stones of Gemstone Beach”

I recently sold some tumble-polished fossil worm cast stones to a Rock Shop. I thought I would provide the Shop with a photo-book about the stones so that customers would have a bit of background about them.

I have produced photo-books before, using a New Zealand-based online site, about holidays and overseas trips. I have also done some calendars through this site. Its products are quite good when working with photos but I sometimes struggle when text is involved – it can be tricky to place text correctly on a page. I chose to put together a 20 page book, 20 cms wide and 20 cms high, small enough to fit on a shop shelf but large enough for decent-sized photos.

The other tricky part of using an online site is getting the brightness of the photos right. How good a photo looks on a laptop screen depends on how tilted the screen is. I have learned to order an initial copy of a calendar or photo-book and check the photo quality and text placement before finalising a project.

The following are the front cover and first three pages of “The Trace Fossil Stones of Gemstone Beach”. The “Introduction” is important for such a book, giving the reader an immediate idea about the topic but also intriguing them to want to know more.

There are four later pages on which text is provided in the book. The first (page 3) is a quote from Geoff Chapple’s book “Terrain: Travels Through a Deep Landscape” about the worm trace fossils at Tihaka, near Gemstone Beach. This provides verification for the nature and age of the trace fossils. Secondly, on page 5 is an introduction to “Trace Fossils” as one type of fossil, supported by photos providing the broader context of marine trace fossils in New Zealand. Thirdly, on page 6 is a brief reference to the diversity of the trace fossils in Gemstone Beach stones. Fourthly, page 13 contains a brief description of rotary tumble polishing.

One of the key aims of the book is to show photos of the great diversity of trace fossil stones from Gemstone Beach. Another is to provide an appreciation of the beach on which they were found. 

Given that the book promotes a certain type of stone that I have tumble-polished, I decided to include other examples of my tumble-polished stones from different places: Gemstone Beach, Birdlings Flat and Riverton. The book finishes with some information on TumbleStone Blog – in case someone wants more information about trace fossil stones – and a list of the sources of information used.

I have done one other photo-book on stones and am thinking of a couple more. But they take time and patience, and I am intending to undertake another stone collection trip to the South Island soon.

South Island Stone Collecting Trip, May/June 2020 – Days Six to Ten

As mentioned in the first Post of this Series, I am undertaking a three-week stone collecting trip to the South Island by car. I am posting up-dates on Facebook for family and friends, then re-posting them here. 

Day Six, Gore to Riverton, Visit to Back Beach – A cold but sunny day in the south! Arrived at Riverton at lunchtime. Visited the Back Beach for about 45 minutes as the late afternoon sun was going down. Were a few people there, enjoying the end of the first long weekend under Alert Level Two. 

The stones on the Back Beach are a very mixed bunch. Most are rough and don’t look good candidates for polishing. However, I have often been surprised at how well they turn out after spending time in the tumbler barrel. The key is to see the potential of the colours and patterns. I found very few fossil worm cast stones despite them having been much easier to find earlier this year.

Day Seven, First Visit to Gemstone Beach – Warmish cloudy day, spent three hours on Gemstone Beach with my sister Helen. About 10 other people were on the beach at different times as well, one was a local collector of hydrogrossular garnets I had met before, and three were Czech people stranded in NZ by the Covid-19 pandemic, undertaking a South Island tour in Level Two. Helen and I first went to the left of the carpark where stones are not usually deposited on the beach. Today there was a good selection there. 

We then dropped our initial finds off in the car before walking to the right, past the Taunoa Stream. About 500 metres in that direction we started to find a few small hydrogrossular garnets. Overall, many interesting stones on the beach.

Day Eight, Second Visit to Gemstone Beach – Another warm day, spent four hours on Gemstone Beach with my sister Helen. We timed our arrival for just after high tide and decided to move westwards along the beach towards the Waimeamea River mouth, just over one kilometre away. However, we were initially unable to cross the Taunoa Stream so spent 30 minutes or so on the beach near the carpark until the tide went out a bit more and the Taunoa Stream went down. We then made our way towards the Waimeamea River, arriving there about two and a half hours later, collecting stones all the way. 

Another hour saw us back at the carpark, just as a cooler breeze was getting up. We found a few hydrogrossular garnets, as well as some nice specimens of fossil worm cast stones, along with a good number of colourful and interesting patterned stones likely to respond well to tumble polishing.

Day Nine – Too wet and windy, stayed inside.

Day Ten, Third Visit to Gemstone Beach – A cold front moved through yesterday and the temperature has dropped. However, I dressed warmly and headed to the beach. Ended up spending five hours there. Arrived just before high tide, and the waves were high and powerful, forcing me initially to look for stones at the foot of the cliff at the back of the beach. 

I went about one kilometre past the Waimeamea River mouth, further than I have gone before. I dropped off a couple of stashes of stones along the way to pick up when returning, so my backpack would remain as light as long as possible, though by the time I got back to the carpark it was quite heavy!

See here for the next Post in this Series.

Alert Level Two, Saturday 23 May – Stone 5, Fossil Worm Cast Stone from Gemstone Beach

This is a small green-grey argillite stone with a number of small fossil worm casts and some dark veins. I have found such stones on beaches at Riverton and near Orepuki. This one comes from Gemstone Beach.

Close-ups reveal more details about the dark veins and the worm cast trace fossils:

The process of producing the images and the close-ups, using three stages of cropping along with saturation, “lightening”, and some “shadowing” (to darken the veins):


Stay-at-Home Day Twenty-One, Wednesday 15 April 2020: Stone Twenty-One

At the end of Week Three, Stone Twenty-One is another fossil worm cast stone. This stone is a medium-green argillite, the trace fossils being light green. Such a colour combination is the most common for worm cast stones at Gemstone Beach and Riverton. Argillite is a hardened, slightly recrystallised, mudstone. The darker in colour it is, the finer grained it is. 

Some of the traces on this stone are chevron shaped.

What is unusual about this stone is that some of the fossil casts or trails appear elongated, maybe stretched from the pressures that turned sediment to rock over thousands of years. 

This is the fourth worm cast stone featured in Week Three of Stay-at-Home:

The next Post in this Series is Stay-at-Home Week Three, Stone of the Week.

Stay-at-Home Day Nineteen, Monday 13 April 2020: Stone Nineteen

Stone Nineteen is the third fossilised worm cast stone this week. But it is a very rare black one. I found it on Gemstone Beach. 

The fossil traces on Stone Nineteen are different from those on Stones Fifteen and Seventeen, being less linear. In at least three instances, we are viewing the worm cast or trail from above, as it were, as it emerges from the depths of the stone.

Stones Nineteen, Seventeen and Fifteen, three different fossil worm cast stones:

The next Post in this Series is Stay-at-Home Day Twenty, Tuesday 14 April 2020: Stone Twenty.

Stay-at-Home Day Seventeen, Saturday 11 April 2020: Stone Seventeen

Stone Seventeen is a newly polished fossilised worm cast stone found on Gemstone Beach just over a month ago. 

Compared to Stone Fifteen, another worm cast stone, the traces are a different colour (dark brown) as is the stone (a greener grey). There are numerous traces across all of the stone’s surface, some of them chevron shaped but others a more solid trail.

I “pushed” the colour of the photos, using the “saturation” option in my Picasa photo software, with the following results:

The green has taken on a more lime hue and the traces are more purple in tone.

Together, Stones Fifteen and Seventeen demonstrate some of the wide variation amongst fossilised worm cast stones on the southern beaches between Orepuki and Riverton.

The next Post in this Series is Stay-at-Home Day Eighteen, Easter Sunday 12 April 2020: Stone Eighteen.

How Much Does Tumbling Wear Away Trace Worm Cast Fossils?

Tumble polishing fossilised worm cast stones has a different aim from polishing other stones because it is important to preserve the traces on the surfaces of the stones. Tumble polishing is normally a process involving the smoothing of a stone by wearing away its outer layer. Sharp edges, pits and nicks in a stone can be removed by tumbling in a coarse grit. But such a tumble for a worm cast stone may very well destroy what makes the stone interesting.

For this reason, I ignore any “imperfections” in the stone itself and seek solely to polish the trace. In order to do this, I tumble worm cast stones once in 320 grit, the finest (least coarse) grit that I normally use, before putting them through a pre-polish then pro-polish tumble.

The other day, a question arose in my mind. How much does that 320 grit tumble change or even damage a worm cast trace? I don’t know for sure, though I have had no reason so far to think it is a problem. But why not take a closer look to find out? So I decided to photograph some fossilised worm cast stones before and after a 320 grit tumble, so I could see any changes.

I chose 40 worm cast stones of varying sizes, colours and types. I then arranged them by size, in groups of four, and took photos of them, front and back, before tumbling them for a week in 320 grit.

 I wet the stones for these photos so that the traces would show better. The following are the first eight stones:

1-4 a before
One side of Stones #1 – #4, before 320 grit tumble.
1-4 b before
Other side of Stones #1 – #4, before 320 grit tumble.
5-8 a before
One side of Stones #5 – #8, before 320 grit tumble.
5-8 b before
Other side of Stones #5 – #8, before 320 grit tumble.

After the 320 tumble in late March/early April, these stones looked like this:

1-4 a after
One side of Stones #1 – #4, after 320 grit tumble.
1-4 b after
Other side of Stones #1 – #4, after 320 grit tumble.
5-8 a after
One side of Stones #5 – #8, after 320 grit tumble.
5-8 b after
Other side of Stones #5 – #8, after 320 grit tumble.

I next compared the before and after photos of each stone in order to gain an idea of the effects of the 320 grit tumble. The next Post explains the differences for Stones #1 to #8.

Stay-at-Home Day Fifteen, Thursday 9 April 2020: Stone Fifteen

Stone Fifteen is a greenish-grey argillite stone with the trace fossils of worm casts in it.  I found it on Gemstone Beach and it came out of the polishing barrel last week.

A “trace fossil” is a fossil not of the animal itself but of some trace it has left behind, such as a footprint, dung or a burrowing tunnel. Fossilised worm cast stones come in a wide variety of patterns and colours. I especially like the chevron trails such as the ones in this stone. 

The first of a series of Posts on fossilised worm cast stones can be found here.

The next Post in this Series is Stay-at-Home Day Sixteen, Good Friday 10 April 2020: Stone Sixteen.

TumbleStone Calendar 2020

Happy New Year wishes to everyone!

In December I moved house from Cambridge to Whanganui. Everything was shifted by Christmas, and most of the unpacking has now been done.

However, the shed I will use for tumble polishing is still in the process of preparation.

Early in January, after the moving and unpacking, I quickly put together a calendar for 2020, using Diamond Photo online. For each month, the Calendar has a set of photos, just slightly smaller than an A4 page, with another A4 size page below it containing the month’s dates. The main internationally-recognised holidays are noted, along with some of the main New Zealand ones.

I was very pleased with the quality of the finished product.

If you want to buy one for yourself, email me at It will cost you $25 (postage included, in New Zealand).

The following are the sets of photos for each month in the Calendar – these are all photos I took in 2019, most but not all of which appeared on TumbleStone blog last year:
January – Riverton scenes
February – Close-ups of Gemstone Beach stones
March – Fossil worm casts in rocks at Tihaka Beach, near Riverton
April – Hydrogrossular garnets
May – Gemstone Beach scenes
June – Fossil worm cast stones
July – Larger stones found on Gemstone Beach and the beach near McCracken’s Rest
August – Polished stones from Gemstone Beach
September – Henderson Bay scenes, Riverton
October – Polished stones, collected by my sister Helen on Gemstone Beach
November – Close-ups of fossil worm cast traces
December – Polished stones, collected by Sam, my sister’s grandson, on Gemstone Beach.

“Here Is Where The Heart Is… Sea Winds Out On The Wild”

Out on the beach, in the wild wind and salt spray, the waves roaring in, the wet stones glistening in the winter sun – my Scottish ancestors must have known something like this…

Photos from the last three days spent by me on Gemstone Beach, finding many fossil worm cast stones, a lot of them too big for tumble polishing…



Wolfstone’s song (below) expresses Scottish ties to land, coast and sea, as well as their disruption and loss through the Clearances and emigration. Runrig’s song (further below) speaks of the modern Scottish recovery of identity and the struggle for more control over national direction.

“Here Is Where The Heart Is” by Wolfstone

Here is where the heart is, beats out like a drum
Here is where the Mavis* flies, where she once came from
Here is where the mother tongue resides,
Far from the hands of hate and greed and lies.

This is where my home is, the shore, the sea, the sand
This is where my family were raised from working hands
This is where the toil and sweat and tears
Knew only hardship through those working years.

From farm and croft and residence, they cleared them from the land
Families of young and old with one wave of a hand
Were sent on board to sail the ocean wide
To a stranger’s land o’er wind and sea and tide.

Here is where the heart lies, like those who’ve been before
Here there are no broken ties with brothers on the shore
Here is where the spirit will return
No more to sigh, no more to weep and mourn.

Here is where the heart is, beats out like a drum
Here is where the Mavis flies, where she once came from
Here is where the mother tongue resides,
Far from the hands of hate and greed and lies.

*”Mavis” = Song thrush.

Recovery” by Runrig

Watching the morning come in on the land
See the moon roll over Skeabost
See the young men late in the glen
All with camans* in hand

Sea winds out on the wild
Sea waves crash onto Uig
See the black homes strung out in a line
Across the island of Skye

I can’t believe
That it’s taking all this time
I can’t believe
My life and my destiny
After the clans, after the clearings
Here I am

Should have been home before daylight
It’s not easy when you’re down and hungry
One from the late run rolled up in a coat
I make my way across the moor

For a late summer in ’84
But now there’s a new day dawning
I’ve heard the Braes men talk in Portree
The news from Glendale

And I can’t believe
That it’s taking all this time
I can’t believe
My life and my destiny
After the clans, after the clearings
Here I am

Still the morning comes in on the land
See the new sun red and rising
See the corn turn ripe in the fields
See the growth in the glen

And MacPherson’s in Kilmuir tonight
What a night for a people rising
And oh God, not before time
There’s justice in our lives.

*”Camans” = The sticks used in the game of hurling.