New Mineral Named After GIA’s John Koivula
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 Post subject: Asterism
PostPosted: Fri Nov 30, 2007 1:14 pm 
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Joined: Sun Nov 12, 2006 2:13 pm
Posts: 189
Hi

On the topic of "what's wrong with this picture" - I like this color-coordingated diagram of needles oriented with crystal faces, but in the accompanying drawing of the star sapphire, the rays don't make sense to me. Shouldn't the rays be perpendicular to the rutile/growth lines/crystal faces (maybe it is a Ti diffused diagram)? I am asking because I keep seeing illustrations like this where the rays are slightly off and I might be misunderstanding something basic. http://socrates.berkeley.edu/~eps2/wisc/Lect8.html#Inclus

I love studying phenomenal materials.... This one is my pride:
http://www.nordskip.com/rose.html


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PostPosted: Fri Nov 30, 2007 1:21 pm 
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Joined: Sun Oct 16, 2005 12:42 pm
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Hi,

The confusion may come from the fact that is hard to draw in the needles and the produced reflections. It soon becomes a mess.
When the needles are orientated =, then the reflection will be |.

Maybe the images on the sheen page are a bit more clear. Although I admit you'll need some imagination.

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PostPosted: Fri Nov 30, 2007 1:30 pm 
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Doos wrote:
The confusion may come from the fact that is hard to draw in the needles and the produced reflections.

Do you have a recommendation for a drawing program? The ones that you turn out are great. I have Adobe Illustrator, but haven't learned how to use it.... meanwhile I sit here drawing by hand; currently for a spectroscopy workshop I'm giving.


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PostPosted: Fri Nov 30, 2007 2:15 pm 
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Hi,

Blender.

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PostPosted: Fri Nov 30, 2007 5:35 pm 
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Joined: Wed Nov 23, 2005 12:47 pm
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Quote:
Do you have a recommendation for a drawing program?



Corel Painter.

... must have mentioned it a few times. I've been using only this since version 6.0 and not it reached 10 :lol:

It is an easy vector and natural medium 2D only drawing program. Easy to transfer stuff from scanned hand drawing like you've been doing, using transparent layers. There is a 30 day trial version (complete) you can play with. Not sue how attractive that price is though. I have it from work. :?


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