PC Rocks, That Is All

Rocks.
That's all.
Click to expand...
Since you pointed out awhile back that you are a geologist, I wanted to know why some rocks seem to form in uniform patterns.

This link below shows some Magnetite but it looks as if someone through together a bunch of triangles.

Why would something be found like that?

https://en.wikipedia.org/wiki/Magnetite

You can click on the photo to get a closer look.

 
<snipped for space>
Click to expand...
The short answer is crystallization. It happens when the atoms have the opportunity to arrange themselves into repeating structures. The variables are pressure, heat, time and weathering (plus others).

https://en.wikipedia.org/wiki/Crystallization

There are some oddities such as the chernobylite crystals which are only found in the corium at Chernobyl.

There are also crystals that have a structure that repeats over time, never truly becoming a single solid crystal. These are called time-crystals are are about the single most Dr Who sounding substance we have found :-)

https://en.wikipedia.org/wiki/Time_Crystal

 
Crystals yes, sorry about that. But look how at the straight lines. How can that happen naturally?
Click to expand...
Oh, right :-)

That largely depends on how the molecules fit together. Different shaped molecules will tessellate together in different patterns. Cubic and hexagonal are very common ones.

This vid explains it far better than I could...

 
Last edited by a moderator:
Crystals yes, sorry about that. But look how at the straight lines. How can that happen naturally?
Click to expand...
As Gronk said, Chemistry bits :) That first vid is really well done (haven't watched the second yet).

Reminded me of how I used to remember the difference between ionic & covalent bonds.

-- I'd think "Iconic" instead of "ionic", as Iconic sort of means 'one' or 'singular'

-- for covalent, well, it was easy to think of this as 'codependent' or 'couple'. more than one. (had a wild n crazy gf that semester)

If you want more you might try searching for "chemistry molecular bonds" & "chemistry cubic structures".

For some really cool (to me) stuff you might look at https://en.wikipedia.org/wiki/Tempering_(metallurgy) since tempering is basically the intentional manipulation of how much and what type of crystalline structures a piece of steel will have.

 
Oh, right :-)
That largely depends on how the molecules fit together. Different shaped molecules will tessellate together in different patterns. Cubic and hexagonal are very common ones.

This vid explains it far better than I could...

Click to expand...
Thanks for the two links. The second one was even better. But one thing that I don't understand is how do you get squares and triangles

out of round drops of salty water. Some did seem to start forming round but still formed straights edges.

Seems that they should have formed round like the drop but they didn't.

 
Thanks for the two links. The second one was even better. But one thing that I don't understand is how do you get squares and trianglesout of round drops of salty water. Some did seem to start forming round but still formed straights edges.

Seems that they should have formed round like the drop but they didn't.
Click to expand...
Well spotted that the centres are often far more chaotic than the full grown crystal. :-)

I'll try to explain this in simpler terms.

The molecules have an easier time bonding with other molecules if the pattern has no flaws. Over the course of time the areas where the pattern has no flaws grow faster than those areas that do have flaws. What you're seeing is that part of the pattern which has grown the fastest, often swamping and smothering the other crystal edges that are forming and stopping them in their tracks. This causes a chaotic centre surrounded by a very uniform shell.

 
Well spotted that the centres are often far more chaotic than the full grown crystal. :-)
I'll try to explain this in simpler terms.

The molecules have an easier time bonding with other molecules if the pattern has no flaws. Over the course of time the areas where the pattern has no flaws grow faster than those areas that do have flaws. What you're seeing is that part of the pattern which has grown the fastest, often swamping and smothering the other crystal edges that are forming and stopping them in their tracks. This causes a chaotic centre surrounded by a very uniform shell.
Click to expand...
So it's kind of like a key and a lock. The atoms fit best in a uniform pattern. Pulling other atoms to it as it grows and attach themselves best at those points.

I see now.

Thanks.

 
Crystals yes, sorry about that. But look how at the straight lines. How can that happen naturally?
Click to expand...
Because crystals are natural. =P

If a magma pocket very slowly cools down then crystals can form. Minerals have very specific axis along which they want to bond, given the chance. The random part is the occurrence of the conditions, not the shape of the crystal.

 
Since you pointed out awhile back that you are a geologist, I wanted to know why some rocks seem to form in uniform patterns. This link below shows some Magnetite but it looks as if someone through together a bunch of triangles.

Why would something be found like that?

https://en.wikipedia.org/wiki/Magnetite

You can click on the photo to get a closer look.
Click to expand...
Yeah it's due to the crystalline shapes certain mineral compounds form in nature. I'm not a chemist, so I can't explain exactly why these crystal forms take the form they have, but think for example of carbon. In graphite for example, the carbon atoms are arranged quite differently then in diamond, even though they are completely made up of pure carbon, resulting in very different material properties.

Some minerals (like galena, the lead ore modelled here in-game) have a rather cubic shape, whilst others are more hexagonic or monoclinal etc.

Hope this helps!

- - - Updated - - -

The short answer is crystallization. It happens when the atoms have the opportunity to arrange themselves into repeating structures. The variables are pressure, heat, time and weathering (plus others).
https://en.wikipedia.org/wiki/Crystallization

There are some oddities such as the chernobylite crystals which are only found in the corium at Chernobyl.

There are also crystals that have a structure that repeats over time, never truly becoming a single solid crystal. These are called time-crystals are are about the single most Dr Who sounding substance we have found :-)

https://en.wikipedia.org/wiki/Time_Crystal
Click to expand...
Dude, you are stealing my thunder! Even though weathering does not have an influence on the pure shape of the crystals.

 
Because crystals are natural. =PIf a magma pocket very slowly cools down then crystals can form. Minerals have very specific axis along which they want to bond, given the chance. The random part is the occurrence of the conditions, not the shape of the crystal.
Click to expand...
*Throws down my pet-rock*

Looks like everybody is a geologist here now! ^-^

Yeah you are right. If magma cools sufficiently slow you can get very nice and large crystals, also called plutonic rocks (granite, for example). If the magma extrudes to the surface, it cools down much more rapidly. Because of this, there is not enough time to form large crystals, because of which you can get a more 'homogenous' rock (basalt, for example).

 
*Throws down my pet-rock*
Looks like everybody is a geologist here now! ^-^

Yeah you are right. If magma cools sufficiently slow you can get very nice and large crystals, also called plutonic rocks (granite, for example). If the magma extrudes to the surface, it cools down much more rapidly. Because of this, there is not enough time to form large crystals, because of which you can get a more 'homogenous' rock (basalt, for example).
Click to expand...
We should be able to make obsidian knives and spear tips.

 
Dude, you are stealing my thunder! Even though weathering does not have an influence on the pure shape of the crystals.
Click to expand...
I'm so sorry about this, the pedantry is too hard to resist...

Technically, a stalactite is a crystal sometimes made entirely from the weathering of the rocks above.

 
I'm so sorry about this, the pedantry is too hard to resist...
Technically, a stalactite is a crystal sometimes made entirely from the weathering of the rocks above.
Click to expand...
Yeah that's true, but it's pedantry like you said :) But calcite is still calcite, whether it is deposited in-situ, is cemented into the sedimentary rock, or whether is dripping down a cave ceiling.

 
We should be able to make obsidian knives and spear tips.
Click to expand...
Sounds like a mod because in this game it's not super hard to get iron tools so it would be a largely pointless feature.

 
I'm so sorry about this, the pedantry is too hard to resist...
Technically, a stalactite is a crystal sometimes made entirely from the weathering of the rocks above.
Click to expand...
First you think u know more than gaz about 7 days to die coding. Then you think you know more than MadMole about game design. THEN you think you know more than Davega about rocks. Next thing you know, you will be trying to teach me how to be a stripper.

 
First you think u know more than gaz about 7 days to die coding. Then you think you know more than MadMole about game design. THEN you think you know more than Davega about rocks. Next thing you know, you will be trying to teach me how to be a stripper.
Click to expand...
You want more tips? The trick is to spin around your own pole :-)

Everyone can make a mistake, I'm no exception. It's not obvious that a stalactite is a crystal and, if memory serves, not something I was taught in either science or geography.

The horrible thing? I generally google for verification these days instead of education. I've been a pedant for so long I've pretty much researched everything that interests me. You want to see me bamboozled? Ask me anything about popular culture :-)

 
You must log in or register to reply here.
Back
Top