Sylvite hopper crystals

Jbailey · Post by **Jbailey** » Wed Dec 31, 2008 5:49 pm

This photo is of home-grown "hopper crystals" of Sylvite (Potassium Chloride). Hopper crystals often form when there is inadequate solution circulation to feed the entire crystal face.
In this case I deliberately starved the crystal growth.
Lighting is from behind and above.
Crystal mass width about 1.5"

Jim

elf · Post by **elf** » Wed Dec 31, 2008 11:02 pm

Very Fibonacci like. Would it be possible to grow one that was even more so?

Cyclops · Post by **Cyclops** » Thu Jan 01, 2009 4:19 am

Lovely shot Jim!

Jbailey · Post by **Jbailey** » Thu Jan 01, 2009 1:14 pm

Thanks for the comments and praise. I finally found some subjects to photograph indoors.

Elf:

The crystals' preferred growth is cubic. The spiral habit is from the lack of solution saturation causing fresh starts, I believe.

Any finer control approaching a finite mathematical pattern would be something for a physical chemist to try. Are there any out there?

Jim

rjlittlefield · Post by **rjlittlefield** » Thu Jan 01, 2009 1:34 pm

Very interesting structure, well photographed.

For those interested in the physics, a good place to start is with "Crystal Growth for Beginners". This is a college-level textbook, viewable in part online through Google Books. The section about spiral growth is on page 218, HERE.

--Rik

Charles Krebs · Post by **Charles Krebs** » Thu Jan 01, 2009 2:08 pm

Jim... very nice! I really like the modulation of the light passing through the crystals. It might also be fun to do a couple of higher magnification shots in "tight" on the patterns and light.

Leave it to Rik to give a reference to pages of mathematical formulae about crystal growth!

As it says at the bottom of this "clip"... I saw it immediately... but after all, this is only "Crystal Growth for Beginners".
Couldn't you find something a little more for experts.

( just kidding Rik ... I'm pretty techy myself, but I envy people that can make heads or tails of this type of "treatment" )

rjlittlefield · Post by **rjlittlefield** » Thu Jan 01, 2009 3:08 pm

Hey, I have a reputation to uphold here, and I figured I might as well start the New Year right!

In defense, I'll note (giggling) that you've exaggerated a little. The page that I linked has only a diagram and some isolated Greek symbols, no equations.

Of course it's also true that the equations you quote are from only four pages earlier, and I guess they're part of the mathematical run-up to the diagram.

But I'm not sure, because I didn't struggle through them either!

--Rik

Jbailey · Post by **Jbailey** » Fri Jan 02, 2009 11:44 am

Wow! Did I ever get a response. Thanks to you all. This is quite a bit of feedback from 10 cents worth of chemicals that have laid in storage for 20-30 years.
I will post another type of hopper crystal next.

Jim