Amazing 50 foot crystals found

I read about that cave a couple years ago I think. Truly an amazing thing. I hope the mining operations do not damage the crystals. Or that bungholes break into that place to steal (or perish the thought seek to destroy).

We humans are so shortsighted and selfish. I can't begin to imagine how many thousands of years it must have taken for such vast crystals to form. It would be a shame if they came to harm because of ouyr petty greed.

Peace.
 
Amazing.

Technically, though, are they really the largest crystals? I would have thought that some icebergs might be larger, though not as interesting.
 
Mariner said:
Crazy pictures. I'm sure I've seen episodes of old Sci-Fi series which must have been filmed there! ;)
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It struck me that it looked a lot like the arctic "Superman" set or vice versa!
images
.
 
Not that i Have anything to counter it, but why do you think icicles are single crystals?

p.s. I loved the power point presentation where they have "we must protect these" coupled with a ton of pictures of people climbing all over them and posing with their hands on them. YAY CONSERVATION!
 
RussSchultz said:
Not that i Have anything to counter it, but why do you think icicles are single crystals?
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Just an educated guess. Not all will be, obviously, but the example image looked like a good candidate.

My reasoning was thus:
Ice is a crystalline structure (according to wikipedia). Icicles tend to "grow" slowly, which I likened to the way you can grow a larger crystal from a small 'seed'.

Also, Wikipedia suggests that the formation of stalactites are also a form of crystallisation so it seems logical to me. <shrug>
 
Back when this had its last round here, I think I read somewhere that they shut down the cave after noting that some of the crystals had become dim from the change in atmosphere. And that they wouldn't let anyone in except for scientific research. No tourism.
 
Simon F said:
Just an educated guess. Not all will be, obviously, but the example image looked like a good candidate.

My reasoning was thus:
Ice is a crystalline structure (according to wikipedia). Icicles tend to "grow" slowly, which I likened to the way you can grow a larger crystal from a small 'seed'.

Also, Wikipedia suggests that the formation of stalactites are also a form of crystallisation so it seems logical to me. <shrug>
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Crystals tend to have hard edges, because crystalline structures can only have edges at particular angles. Thus icicles are not likely to be singular crystals. Ice crystals tend to be microscopic.
 
Chalnoth said:
Crystals tend to have hard edges, because crystalline structures can only have edges at particular angles. Thus icicles are not likely to be singular crystals. Ice crystals tend to be microscopic.
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I guess you've never seen a silicon crystal before they cut it into wafers? ;)

The boundaries of a large, single crystal don't necessarily conform to it's lattice structure (unit cell symmetry). In fact, turbine blades for some aircraft engines are now grown as single-crystals because the primary failure mode at high temps is grain boundary creep (though at lower temps polycrystalline is stronger). Imagine building a 3D structures out of "pixels" that have an inherent geometry (cubic, triclinic, monoclinic, othorhombic, etc.)...these building blocks are made of only a handful of atoms so making an irregular structure is no harder than making a circle with square pixels on a monitor.

That said, icicles are not single crystals. They don't "grow" the way crystals do (nucleation and growth driven by kinetics and thermodynamics), but rather they grow when water melts...slides down the roof and down the icicle and then re-freezes. Not even remotely similar.
 
Mize said:
I guess you've never seen a silicon crystal before they cut it into wafers? ;)
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Aren't those carefully manufactured/polished to be yclindrical in shape (something I never did understand why since surely it must produce tons of waste at the edges)?




Peace.
 
Basic said:
Back when this had its last round here, I think I read somewhere that they shut down the cave after noting that some of the crystals had become dim from the change in atmosphere. And that they wouldn't let anyone in except for scientific research. No tourism.
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BORING! Hooray, there's a treasure hidden where no one's allowed to see it. :rolleyes:
 
Rainbow Man said:
Aren't those carefully manufactured/polished to be yclindrical in shape (something I never did understand why since surely it must produce tons of waste at the edges)?
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The silicon isn't cut into a cylinder from a hard edge; it's grown as a cylinder. After heat treating/melting/purifying silicon in a large vat container, a seed crystal is dipped in and the soupy silicon grows around it while it is cooled as it is slowly raised out and rotated, achieving the cylindrical structure. The whole process is extremely slow in order to get a more uniform diameter as the cylinder will be larger towards the end.

A diamond blade cuts the silicon ingot into the wafers, and then the target surface is polished for lithography.

More info: http://en.wikipedia.org/wiki/Czochralski_process
 
As AlStrong says, silicon wafers come from grown silicon single crystals. Defects in the crystal produce defective chips. The reason it's taken so long to get to HUGE wafers is that it is tough to grow the crystals that large.
 
Mize said:
As AlStrong says, silicon wafers come from grown silicon single crystals. Defects in the crystal produce defective chips. The reason it's taken so long to get to HUGE wafers is that it is tough to grow the crystals that large.
Click to expand...
I seem to remember that they're also picky about the orientation of the lattice structure, such that the cut wafers expose a specific lattice edge.
 
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