Posted by: Rose | October 15, 2013

Lundy, again

Paddled to Lundy, again. I’ve written about this lovely granite isle before, here and here. However, Lundy isn’t just granite. One small area around landing beach and Rat Island contains the ‘country rock’. This was the existing rock that the granite magma forced its way into. You can see the Morte Slates Formation when you land on the island and head up the track (to the pub!). The point where the granite and the slate meet is called the ‘contact’. You’ll have to take my word for it, as I don’t have any pictures. Guess that’s an excuse to go back…

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Rat Island and the landing beach, a corner of Morte Slates on a granite isle

Five paddled from Lee Bay, one fine Friday evening. Beautiful summer conditions and the novel experience of a divorce boat (read double kayak). I’d actually recommend doing long crossings in a double (assuming you get on with your par’ner), as it’s delightfully sociable and I felt so rested that I could have turned around and paddled straight back! Our bearing was slightly off so we arrived at the north end of the Island, not that it mattered particularly because the advance party had thoughtfully ordered food for us in the Marisco Tavern; we were on the brink of being too late for dinner!

Saturday saw us paddling clockwise around the island with the others. Towering tors, lazing seals, challenging lunch spots and an exciting bouncy journey down the eastside. The circumnavigation of Lundy is still one of my favourites. Indeed, a double kayak allows for time to be photographer; I certainly enjoyed the free ride at the front! I also discovered that the front person doubles as a breakwater – this was somewhat less pleasant.

Whilst we paddled down the east side of the island I picked up the maritime forecast: force 5 easterlies were expected. Well, that extinguished any hope we’d be paddling back to the mainland. The Oldenburg has rather idiosyncratic sailing dates, not ideal for stranded sea kayakers. We would have been stuck until the next sailing, on Tuesday. However, a bit of grovelling secured places for us on the charter boat that the rest of the group were using.

Sunday was as windy as forecast, but this gave me exploration time, something that I missed on my previous visit. And the journey back on the Obsession II was an adventure in itself: a cross between a bucking bronco and a log-flume. A wild ride home! We were quite literally thrown off the boat at Lee Bay so that we could collect our cars. I suppose that’s the service you can expect from hitchhiking.

Did you know that ‘lundi’ is the Icelandic word for puffin? The Norse origin of the word gives reason for the island’s name. The eradication of rats on Lundy seems to be a ray of hope for the island’s puffin population. However, it might be too little too late as rising sea temperatures are causing the northward shift in seabirds’ food, for example the sandeel. It is seems possible that puffins will leave Lundy as they move north in search of food.

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West coast of Lundy

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The crossing

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Ooops, wrong end!

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Nearly there!

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Squeezing between Rat Island

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Granite on a grand scale

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Lounging around

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Many caves for exploring

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Challenging luncheon

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Spectacular west coast

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Bouncy ride round the north side

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Can you spot the 2nd kayak?

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Disused lighthouse

Posted by: Rose | October 6, 2013

Dawn Raid

I was ‘encouraged’ out of bed at 5am. Do not underestimate how unusual this is; I am not a morning person and this was most definitely still the night before. I poked my head out of the tent and confirmed that the wind had dropped. Reluctantly, I got ready to paddle, but knew, deep down, that dawn would be an idyllic time to explore the Western Rocks of Isles of Scilly.

We left Troytown campsite as the rising sun breached the top of St Agnes and were witness to the awakening of the islands’ population of shags, puffins and petrels. Our clockwise circuit of Annet and the Western Rocks took us to the very edge of the Isles. We shocked seals out of their early morning slumber and rode the surprisingly large cross swell back to St Anges in time for breakfast.

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Sunrise over St Agnes

The isolated points of the Western Rocks have not always been so lonely. During the last glacial maximum, 22,000 years ago, ice extended all the way to the Isles of Scilly from the Arctic. The sea level was significantly lower with the ‘missing’ water locked away within the vast ice sheet. In fact, the water level was so low that the ice was grinding upon bare rock; there was no sea around the Scillies!

As the climate warmed, northern Europe was gradually released from its icy grip. Melt water slowly raised the sea level, but the increase was not simply due to melting ice; the thermal expansion of the oceans also accounts for some of the increasing volume. By 4000 years ago, the Isles of Scilly were surrounded by water, but not as we know it. St Martin’s, St Mary’s, Brhyer and Tresco were one island, whilst St Agnes, Gugh and Annet were another. Around Sampson, the remains of field boundaries lie beneath the low tide mark and provide evidence for the changing topography of the Scillies. The ruined settlement on the rocky islet of Nornour was not always on the shoreline.

As the human race releases carbon dioxide from long-term storage reservoirs by burning fossil fuels, the shape of the Isles of Scilly will continue to change. The release of greenhouse gases into the atmosphere will increase the Earth’s average temperature. We are likely to lose all the sea ice from the Arctic, but this will not change sea level since the floating ice is already displacing the same volume of water. We should be concerned about the loss of land ice. Greenland is already disintegrating at an alarming rate. The extent of the impact upon Antarctica’s vast ice sheets remains to be seen. But there is one thing that we can be sure of, and that is the Isles of Scilly are still shrinking.

Check out Mark’s blog for lots of lovely photos, here, here and here.

Post-Glacial Sea Level from Wikimedia Commons

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Dawn light, St Agnes

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Heading back for breakfast. Photo by Mark Rainsley.

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Causeway between St Agnes and Gugh. Its days are numbered.

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Standing stone on St Agnes

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Baking cake and applying nail polish. Who says sea kayakers aren’t glam?

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Nornour settlement

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Eastern Rocks from St Martin’s

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Stained glass in All Saint’s Church, Bryher

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Not bad for a week of many winds

Posted by: Rose | September 30, 2013

Pointy

Bull Point, Morte Point, Baggy Point and just generally pointy rocks. That’s a lot of pointy.

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Morte Point

The northwest tip of Devon is made up of the Morte Slates Formation, a series of muds, silts and sands laid down at the bottom of a shallow sea. They were deposited a mere 359-385 million years ago, during the Devonion period (incidentally Devon is the only British county that gives its name to an internationally recognised geological time period!). At this time, Britain was part of the super-continent Pangaea, located somewhere just south of the equator.

A 100 million years or so later, compression of the tectonic plates created fold mountains and turned these sediments into slates. The compression of the clay minerals caused them to align and create cleavage (no sniggers, I’ve heard it all before). This basically means that the rock now has a weakness and easily splits into layers; a weakness that is easily exploited by the sea that currently pounds the North Devon coastline.

It just happens that the cleavage around Morte Point is very steeply inclined and so erosion creates narrow gullies between the cliffs and the open ocean. These gullies are perfect rock-hopping territory for a keen sea kayaker with a plastic boat (or a well-off kayaker with a fibreglass boat). If you are especially talented you can create a kayak see-saw on the top of a rock….

If you add a little sunshine, a gentle play in Morte races, good company and the obligatory slog into the wind, you get a very pleasant day out.

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Steeply inclined cleavage

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Morte Point

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Morte and Bull Point

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Looking Woolacombe way…

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A mellow Morte Point tide race, on neaps

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Morte race and Baggy Point

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Bull Point lighthouse, and Lundy. Photo not taken from a sea kayak!

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Morte Point on a somewhat less gentle day

Posted by: Rose | June 22, 2013

On the Edge of the Atlantic

There’s a rock on the edge of the Atlantic. It’s called Bishop Rock. It’s battered by swell that’s travelled several thousand kilometres. In 1887 lighthouse #3 was built upon it. The lighthouse is a testament to Victorian engineering and endurance. Without a doubt, the rock will outlive the lighthouse. That lump of granite is designed to be tested by the elements.

Still a long way to go (the rocks on the left are 3.5km from the lighthouse)

Still a long way to go (the rocks on the left are 3.5km from the lighthouse)

Granite is made up of three minerals: quartz, feldspar and mica. They are all silicates (SiO2). It’s called granite because it contains ~70% silica. It’s tough stuff. In fact, the way to identify quartz is to try and scratch it with a steel knife. It doesn’t work because quartz is harder than steel. Quartz is so resistant it becomes the only thing left on sandy beaches; all the other minerals have been destroyed by weathering.

Strictly speaking, the (not very good) photo below is a diorite because it does not contain distinctive pink alkali feldspar. There’s the clear glassy quartz, the white rectangular plagioclase feldspar and black biotite mica. There’s probably some sparkling muscovite mica hiding in there too. The crystals interlock because they grew together as the magma slowly cooled.

St Martin's granite

St Martin’s granite

The workers who built Bishop Rock lighthouse had the daunting task of living upon Rosevear, another exposed lump, 3km east of Bishop. It is only slightly less lonely because it has several neighbours within the Western Rocks. The comfort of St Agnes, the nearest inhabited island 7km away, was apparently a boat trip too far.

Lighthouse #1 was an iron construction that allowed the sea to flow through it. It was washed away in 1850 before it was completed. Undaunted, designer James Walker built lighthouse #2 from granite transported from the mainland. This version lasted 23 years, until storm waves tore the bell from the 35m tower. The storm damaged lighthouse was then strengthened by building the current version around it, another 7 years of work. When the seas allowed work, the masons were tied to Bishop Rock by rope so that they could be hauled back in when they were washed off.

It was a manned lighthouse until 1992. An account by the keeper records seas that reached 20m up the tower, and waves that broke over the light, 49m up. To see Bishop Rock lighthouse today is awe inspiring. For some illogical reason, the door faces southwest into the prevailing wind. It’s a green door.

We had one day of calm weather during our week at the Isles of Scilly. This rare opportunity was grabbed by the horns and we made it! The paddle out there took a little longer than envisaged. The tidal currents weren’t playing ball. The round-about trip from St Martin’s took 7.5 hours. A gentle introduction to a week of many winds! It’s a truly wonderful place regardless of the weather.

Bishop Rock Lighthouse. Photo by Mark Rainsley.

Somewhere off the east side of St Mary's

Somewhere off the east side of St Mary’s

Amazing on St Martin's

Amazing on St Martin’s

Round Island sunset

Round Island sunset

After a three year absence, it’s good to be back rock blogging. It won’t be a one off!

Posted by: Rose | April 27, 2010

Himalayas

My friends have been in Nepal paddling the Bheri, Thuli Bheri and Karnali. I didn’t get to join them, but my consolation is that I’ve paddled the Karnali before and they’ve been stuck in Delhi due to one very inconsiderate volcano. They have gradually escaped India’s capital city over the last 10 days; the final 6 should be fleeing right now….

So it’s not entirely surprising that I’ve been reminiscing about our India trip, 2 years ago. India is a universe unto itself; the sights, the smells and the astounding levels of bureaucracy are mind blowing. I love it! Combining a trip to Mother India with kayaking was my best ever adventure. We explored long stretches of rivers in Uttarakhand and Himachal Pradesh. As the roads follow the rivers, you can just keep going and going and going. I have never been so exhausted and broken.

The final river of the trip was the Sutlej. Its headwaters are in Tibet and it is already a vast river where we joined it at Rampur; there is still a long journey ahead before the water finally joins the Indus in Pakistan. We overnighted on the river, so the sluggish laden kayaks took some getting used to on the big volume water. The river alternated between very big rapids (sufficient to make me and my kayak fully airborne) and stretches of recuperative flat water.

The finale of the river, and the entire trip, was a narrow gorge, covered with the squiggles of ductile folding, that squeezed the river through a narrow gap, creating one very big rapid. We received a final adrenaline high to complete our trip.

Leaving the gorge and entering the biggy. Photo by Mark Rainsley.

 When rocks are subjected to strain they react differently depending on the amount of strain, their depth and their composition. The end result is either faulting or folding. When a rock varies in composition, for example sedimentary beds of sand and mud, both folding and faulting can occur.

Imagine an earthquake at the surface. The rocks are cold and the strain is high and of short duration; the rocks snap apart and create fissures in the ground (a fault). In the Himalayas, two continental plates are converging to create a mountain belt. At depth, pressure and temperature is high and strain is low, but constant. The rocks become plastic and flow and fold, creating ductile folding. The gorge on the Sutlej was convered in small scale ductile folds and very pretty it was too.

Ductile folds in the Sutlej gorge. Photo by Graham Bland.

The Biggy. Photo by Mark Rainsley.

Glassy on the Sutlej. Photo by Graham Bland.

Posted by: Rose | November 23, 2009

Ballad of Glencoe

For me, the Highlands always conjures an image of Rannoch Moor and the mountains of Glencoe. It reminds me of my first visit; we were on our way to an early start up Ben Nevis as part of the National Three Peaks Challenge and I woke to dawn lighting the pass. It was magical then and still remains that way.

Glencoe is composed of volcanics associated with the mountain building of the Caledonian Orogeny, the same event that metamorphosed the sediments in Glen Roy. Glencoe is famed as the location that developed the theory behind the process of caldera collapse. Thousands of cubic kilometres of magma were erupted from the Glencoe volcano, only to leave a huge void within. A ‘ring fault’ was formed which circled the empty chamber. Each eruption caused an internal collapse of the volcano along the ring fault, eventually leaving a vast basin-like hollow called a ‘caldera‘.

The landscape that you now see at Glencoe as been modified by glaciation. The volcanic rocks have been scoured and shattered, leaving behind the distinctive U-shaped valley that the River Coe now flows through.

Entry Falls, River Coe. Photo by Mark Rainsley.

We spent the morning in a Fort William industrial estate trying to fix my broken boat so that it would survive the remainder of the week. It didn’t work. The pressure of the whitewater breached the hull again and I paddled the entire Gorge section with water sloshing over my legs, squealing ‘I’m sinking!’.

Now that I’ve paddled the Coe it’s got my top spot as ‘the river with the best scenery’. I spent the entire time craning my neck trying to take it all in. It really is impossible to get all the mountains into your vision from water level…

O cruel is the snow that sweeps Glencoe
And covers the grave o’Donald
And cruel was the foe that raped Glencoe
And murdered the house of Macdonald.
 

Sinking on Coe Gorge. Photo by Mark Rainsley.

Back Door Man, River Coe.

Entry Falls, River Coe. Photo by Mark Rainsley.

Glencoe. Photo by Ol Renison.

Posted by: Rose | November 20, 2009

Glen Roy

I’ve just enjoyed a wet AND warm week in Scotland. Oh, kayaker’s heaven. It was a case of third time lucky; I finally got some water and experienced a whole array of new-to-me rivers. It was also a chance to encounter the River Roy in its full splendor by paddling from the head of the Glen to Roy Bridge.

There’s something quite special about Glen Roy. The road follows the river, only to come to a sudden termination at the head of the valley. All that lies ahead of you is the catchment divide between the Roy and the Spey, plus a few sheep. The road eventually leaves the trees and the few scattered houses behind and the Glen suddenly opens out into a vista of craggy slopes leading to mountain tops and the river down below. I like to believe that kayakers are the only people who know that this spectacular Glen exists, except that it has one claim to fame….

Parallel Roads, Glen Roy. Photo by Tom Crow.

Glen Roy is renowned for its Parallel Roads. There are three distinctive lines that run across both sides of the valley which are the remains of shorelines from an ice damned lake that filled the valley during the last stadial, the Younger Dryas (Loch Lomond stadial). This cold period lasted a brief 1300 years and terminated around 11,640 years BP*, the start of our current interstadial, the Holocene.

With respect to the geology of the River Roy, the Parallel Roads are less than the blink of an eye. The Roy flows through the Grampian Group and Appin Group, both sediments of Precambrian age (around 750 to 540 million years old) that were deposited in the Iapetus Ocean. These sediments were then metamorphosed during the mountain building of the Caledonian Orogeny which joined England and Wales to Scotland.

The sedimentary layers, metamorphism and consequent schistose fabric (alignment of minerals) within the Grampian Group is the reason for the instability of the geology in the Roy Gorge and the cause of the evolution of the rapids on the river.

*BP means before present and actually equates to 1950, the advent of radiocarbon dating.

PS What is it with Scottish kayaking trips and breaking boats???

Head of the Glen. Photo by Ol Renison.

Wish You Were Here, River Roy. Photo by Simon Knox.

Mamba's days are numbered, Wish You Were Here, River Roy. Photo by Ol Renison.

Escaping Roy Gorge...

Posted by: Rose | November 19, 2009

South West is Best

Way, way back in June I attended Mark’s South West Sea Kayak Meet. It was one of the few occasions this year when I actually got out in a sea kayak (I’ve been locked in battle with DIY, amongst other things). I had a fantastic weekend – lovely paddling, meeting old friends, making new friends, great talks and the Pig’s Nose Inn was its usual bizarre self (the staff thoroughly embarrassed me in exchange for Birthday cake). I don’t think I’ve ever seen so many paddlers on the sea at one time. Great! P&H were also in attendance, so I got a demo boat fix too.

Spot the kayaker, Hallsands. Photo by Anne Hanson.

Saturday brought with it a foggy paddle south of Hallsands, the highlight being seal TV (they sprawled on the rocks, we watched transfixed). I got to paddle a glittery turquoise Quest LV, which I loved. However, I don’t recommend using a VHF tag containing the word ‘glitter’; it upsets the Coastguard!

Atlantic swell, scattered with sunshine, made Sunday’s paddle from Thurlestone Sands a perfect rockhopping opportunity for those who dared. I braved the swell through Thurlestone arch, or maybe it was just a case of demo boat courage?

Thurlestone arch is composed of Permian breccio-conglomerate*. Although the swell didn’t allow for close inspection, it is composed of pebbles (and even boulders) of local Devonian and Carboniferous rocks that were transported by water. This sedimentary rock was created by flash floods in a desert environment, deposited by a wadi.  The very mixed grain size is the result of the sudden cessation of water velocity and the rapid deposition of sediment.

Comparatively, in environments where water velocity decreases slowly, the deposited sediment will gradually decrease in size with smaller and smaller particles being deposited over time (the opposite is never true as increasing water velocity causes erosion and transportation). This sorting of sediment size can be clearly observed in the geological record and is known as a ‘fining upwards sequence’.

A fining upwards sequence can be used as an important tool known as ‘way-up indicator’. It is entirely possible to view rocks that have been completely overturned by folding; they are simply upside down. When it is present, inverted fining upwards can be used as evidence to prove that this is the case.

Here’s to SWSKM 2010…

* A breccia has angular clasts that have been deposited close to source and a conglomerate has rounded clasts that have been smoothed by transportation. A breccio-conglomerate contains a mixture of angular and rounded clasts.

Demo boat courage, Thurlestone arch. Photo by Anne Hanson.

Breccio-conglomerate, Thurlestone arch (you try taking photos of rocks in swell!)

Posted by: Rose | July 1, 2009

Paradise

I’ve finally dusted off the sea kayak; it’s not been out to play since paddling to Lundy back in September. Oh dear. But I feel that I’ve more than made up for it. I have discovered a little corner of home grown paradise. That’s right, I’ve been to the Isles of Scilly….

The bluest blue, North coast of St. Martins. Photos by Mark Rainsley.

The bluest blue, north coast of St. Martins. Photo by Mark Rainsley.

The short few days on the Scillies were enough for me to fall in love with those rocks on the edge of the Atlantic. There is an air of tranquil romance about the place; an idyllic hush merges with the deep blue sea and white sands, all sprinkled with the riotous colour of flowers. Being able to dip in and out of the many islands by sea kayak is just the icing on the cake. Even my sea sickness and the very exciting* crossing back to St. Mary’s to catch the ferry didn’t dampen my spirits and my promise to return.

Unlucky for you guys, the Isles of Scilly is yet another granite. All my kayaking appears to be granite themed at the moment. I must diversify!

The Scilly granite is an outcrop of a large batholith that joins all the Devon and Cornwall granites at depth; it’s just a smaller sibling of Land’s End, Bodmin and Dartmoor (but not Lundy). This granite mass is related to the ending of the Variscan Orogeny. The Variscan Orogeny is a mountain building event caused by the collision of Gondwana (S. America, Africa, Antarctica and Australia) and Laurentia (N. America) that occurred during the Carboniferous and created the super-continent Pangaea.

The heat generated from the granite and the movement of hot fluids through fractures and fissures in the country rock  is the root cause of Cornwall being a historically important mining location for tin (cassiterite), copper, lead, zinc and silver. In addition, the degradation (it literally rots in humid conditions) of the granitic feldspar to kaolinite is also important for the extraction of China Clay. China Clay doesn’t just make china, it even goes in toothpaste and makes paper smooth. It also provided the hole-in-the-ground for the Eden Project.

I’m not sure what happened to taking any kayaking photos; I appear to have gone flower crazy. But there are lots more photos here…

*this means big cross swell and white horses breaking over the deck

The Eastern Isles

The Eastern Isles

Tresco Gardens

Tresco Gardens

A room with a view, St Agnes.

A room with a view, St Agnes.

Salvaged ship figurehead, Tresco

Salvaged ship figurehead, Tresco

Somewhere or other off St Martins

Tean, I think?

Posted by: Rose | May 28, 2009

True Story

Three geologists were returning, on a train, from fieldwork in Scotland.  As you would imagine they were reviewing their trip, basically talking ‘shop’.

They were joined on their table seat by an unsuspecting member of the public, Mr Joe Bloggs. When Joe got up to leave the train, he could no longer contain himself. With more than a hint of worry in his voice, he asked if they were from the MoD. He wanted to know if they had been talking in code!!! The poor man had been sat there the entire journey, terrified that he was eavesdropping upon a conversation of top security.

I was recently talking to an A-Level geology teacher about how the best thing his prospective students can have for studying the subject is a good memory. Like all sciences, geology has a language all of its own.

If I do a quick trawl of my memory, this is what falls out….

hornblende, greenschist, porphyroblast, recumbent folds, allochthonous, pahoehoe, lath, galena, rhyolite, turbidite, dextral, strike-slip, horst and graben, cleavage, groundmass, ophiolite, anticline, psammite, pyroxene, orthorombic, gniess, belemnite, isotropic, ductile and, of course, garnet.

The Ammonite. The world's most popular fossil?

The Ammonite. The public's favourite fossil?

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