Posts from the ‘Non-Thundereggs’ Category

Now THAT’s how to pack a rock!

Now THAT’s how to pack a rock! Genius! And a nice stroke in the war against the great enemy (newspaper) . . .

Now that's how to pack a rock!


Juchem Agate – A Fascinating Non-Thunderegg Interlude


Here’s a real curiosity to keep you going during these wild days while I am deep in book launches rather than mud.  It’s not a thunderegg, it’s an agate nodule from the Juchem quarry, Germany – and it is also one of the most extraordinary textures I have seen in a while.  No matter how beautiful and perfect some banded agate may be, once you have seen it, you have seen it.  In this case, it is agate with a riddle – agate that twists the brain, as you try and work out how on earth it formed and unpick its complexity.  There are two types of calcite and two types of agate – or possibly more of both – that have all grown on top of each other and replaced each other.  White and pink is agate – clear and black is calcite.  A very complex rock.

The Joy of Ocos

They may be one of the most common of all the geodes, almost ubiquitous in any number of rock shops, trinket stalls, museum gift shops etc. – but that shouldn’t blind us to what amazing things they are. Their delicacy and patterning is unique, washed through with gorgeous feathery ‘cloud agate’. This plus the complex crystal caves filled with everything from Amethyst to Goethite and beyond make them possibly one of the most remarkable agates in the world when at their best – and I don’t say that lightly.

For all their ubiquity, it is surprisingly hard to find information about these, maybe partly since nobody can agree on the exact name. I have seen Oco, Coco, Ocho, Ocos etc. Oco is the name given on the Mindat website, so I will go with that one for now. However, I only recently became aware of the fact that there is possibly more than one Brazilian location involved. The classic Oco comes from Três Pinheiros, Fountoura Xavier, Rio Grande do Sul. These stones are dug out of the red-brown earth of the region and form a welcome extra ‘crop’ for the farmers. The following though, is almost certainly a Parana Cloud Agate – Similar but subtly different:

Like a lot of the stones out of Brazil, there is a certain vagueness about their origin – and I can’t pretend to know much at all.  But I am totally blown away by the delicate patterns and sheer intricacy of these stones.  I have now launched a gallery of them in the ‘non-thundereggs’ section of the website.

A Brief Digression from Thundereggs – A Polished Keokuk Geode

I occasionally let my hair down and publish something that isn’t a thunderegg.  This section of the gallery is basically ‘just for fun’ – nothing more than a few different things that caught my usually thunderegg-fixated eyes at some point.  In this case, here is a specimen of one of the most famous geodes in the world – the Keokuk Geodes from Iowa, USA.  These are fairly often seen, but the majority are cracked open rather than polished.  I am personally not a fan of broken rocks, and I think in this case that is born out by the wonderful subtle colours and transparency that are revealed when they are actually cut and polished.  This specimen has a relatively unusual fine band of what I take to be white agate framing the almost solid quartz core (anyone like to correct me?).  It’s not a thunderegg, but it is really lovely I think!

Click here for the small non-thunderegg section of the gallery:

Dulcote Agate – England’s Glory

As a Brit, I have to say that the fact that there are no thundereggs here in the UK is a bit of a frustration.  The nearest thundereggs to where I live are (or were) in the south of France or Germany.  But what about other stones?  In the storm of magnificent rocks from all over the world, it is easy for the UK to get occluded, even when you live here.  Some of the Scottish agates are quite interesting – but true world-class agates from the UK?  Well, here’s one.  The famous Dulcote Agate from Somerset – an exquisite and complex type of nodule known among the agates as England’s Glory, the Mendip Magic-Stone or, less romantically, Mendip Potatoes.

Dulcote Agate

I am generally the least patriotic person out there, not much caring for even the very concept of countries, but I have to admit to feeling a warm glow at encountering an agate from England that can hold its own against any stone in the world!  A very uncharacteristic feeling for me!  Dulcote agates are a British rock that can shake all them foreign agates at the knees!!  Heheheh!

Dulcote Agate

And lets have a plug where a plug is due – I bought these here:

Museum Grade Thames Red Flint – Not so ‘Ordinary’

Warden Point Red Flint

Well – I was hoping to get back to some actual thundereggs next – that’s what this blog is about after all!  But I had to share this with you!  I have been getting more and more interested in the beach pebbles from Warden Point and the Thames estuary, but when i cut this one, my stomach sank in amazement!  I have always called these ‘ordinary’ pebbles – the beauty in the mundane and all that.  But that is starting to sound a bit silly now.  I mean – is there any definition of ‘ordinary’ that fits the above picture?

I have recently launched a new page dedicated to these Thames Flints on my main website.  You can see it here.

Another of those ‘Ordinary’ Beach Pebbles






There will be more updates on the gallery soon I promise!  in the mean time, here is another of those ‘ordnary’ beach pebbles to keep you going – just a stone picked up on a stroll and cut and polished.

Samphire Hoe Geode

This fellow came from Samphire Hoe, near Dover, Kent – though i have no idea whether it came out of the cliffs there, was washed up from further away or was even brought there artificially as part of the construction there (just imagine – a channel tunnel geode!) !

For a seemingly simple beach pebble, it proved almost ridiculously complicated.  As far as I can tell, it is actually a muddled chalcedony/flint geode with quartz crystals, inclusions, very subtle lacy banding in places and flecks of Pyrite, of all things.  You can’t see them very clearly in this scan (there’s some in that little dark area to the lower right of the cave), but catch the light and they flash very vividly.