What are they and how did they exist?
a geode couple
As you know, our earth is about 4,6 billion years old.
At that time the earth was one big burning fireball, as it were our earth “turned to stone”.
Several different kind of rocks were formed, but still things rumbled in the centre of the earth and the
scorching magma tried to work its way out through the ever-thickening crust.
In the beginning this was very easy, but because the crust became thicker and thicker, the eruptions
became less and nowadays it is very rare that such eruptions still occur.
geodes
Going back to what we call ‘geodes’
and then especially to those from Mexico. Somewhere in the region Chihuahua people discovered a lava well
with billions of these frozen gas bulbs.
Nowadays it is harder and harder to dig up large quantities, because the bottom is almost reached.
Imagine standing on the edge of a crater, which is filled with burning, bubbling lava.
At the surface of the burning substance you can see gas bubbles, which have formed in the boiling mass
and splash on the surface.
Ten thousands or even billions of round gas bulbs are on their way from the bottom of the crater to the
surface to escape with a ‘blob’.
But now finally the solidification of the lave starts and it begins naturally on the top.
The gas bulbs which are still on their way, can’t escape anymore and they hang with ten thousands of them
on the ceiling of the stone crust, before called lava. These gas bulbs harden and become encapsulated.
A look in the mine; how do geodes come to the surface?
The mining of the geodes is not that simple. Here you find some photo’s to get a small impression of the
process. A hot desert with sometimes enormous rain showers doesn’t always make it easy. Rain can be the
cause of flooding the mine and than a long time there is no opportunity to mine the geodes.
The shaft The drilling machine
How do crystals form in the geode?
Because there is an enormous heat, atoms and molecules swirl around like crazy inside the gas bulb.
When the mass cools, the atoms and molecules unite with the different elements in the pattern prescribed by nature.
Beacause silica has the habit during the process of cooling to find all the small holes, slots and cracks, it also runs into future geodes,
which makes the geodes harder and stronger than the lava.
Through billions of years the lava is affected by erosion and we are able to mine the “stoned gas bulbs”.
At MTN in Giethoorn you are able to crack the about 60.000.000 years old bulbs with special pliers.
The beauty of the glittering crystals shows you the great miracle of nature.
No man can see from the outside what’s inside the bulb, not even the best experts and geologists!! It’s always a surprise!
Even when you crack 10.000 bulbs, there are never two the same.
What can you find in the geodes?
You can find the following crystals in these geodes:
Calcite/agate geode with rock crystal – amethyst – smoky rock crystal.
The most interesting crystals are those which occur in small amounts.
First calcite crystals are mentioned in their multiple forms.
So we know: clear calcite, brown calcite, calcite towers, calcite pagodas, hexagonal calcite and angel wings calcite.
Further the goethite needles and/or tassels. This is an iron hydroxide or simpler said iron crystals.
