Fun with a Petrographic Microscope
Oh dear...
Was I having a blonde day today or what! I got to my 3hr Geos230 prac and I was gone... I couldn't concentrate at all!
Me: Francis, have you done sample 8.1 yet
Francis: Nope
Me: can you?
Francis: sure...why?
Me: i can't find the multiple twinning in Chloritoid anywhere! It's sposed to be really clear but I can't find it. Can you?
Francis: Did you flip down the polaroid lense.
Me:..........Ohhhh! I'm an idiot
Most of you who read this blog are no doubt, confused and not amused. I'll explain. See, I'd like to think of myself as actually quite good at mineral identifications. Multiple twinning happens frequently on a mineral called Plagioclase and it looks stripey, but only under polarised light. Me, looking at the stupid mineral in plain light, saw nothing but this...
Of coarse you can't see multiple twinning under plain light! You need to polarise it so it looks like this...
This is something I should have known... and this is why for 10 minutes after I was laughing and banging my head on the desk!...
Things picked up from there though. Soon after that to my surprise, my brain started working again...Huzzah!
Nathan, the Tutor only proving my brain was working...
Me to Nathan: Is there such thing as Chrinoidal Limestone?
Nathan to me: Yes there is!
*Whoot!*
Me to Francis: No. There's no Hornblend. It's all biotite, the extinction angle is zero. There does seem to be some discolouration caused by chemical alteration in the biotite though.
Nathan to Francis: It's biotite. It's been partially altered to form chlorite.
*Whoot!*
Me to Alex: I think it's biotite. It may have just been smudged though. That would explain the wacky birefringance!
Nathan to Alex: No! It's not Biotite. It's a mineral we haven't encountered yet!
*Well, 2/3 isn't too bad...Whoot anyway!*
Later I was amused to find that Alex's pencil case which is one of those ones you can slide letters into to spell your name, did not actually say Alex on it. It said John. Supposedly that is it's name. That was funny enough without Francis pointing out the fine print to me above and below the name John!
I am a pencil case
Hello my name is
JOHN!
My owner is a lovely girl named ALEX!
Well... that was my bizarre Geology lesson!
CU Soon!
Was I having a blonde day today or what! I got to my 3hr Geos230 prac and I was gone... I couldn't concentrate at all!
Me: Francis, have you done sample 8.1 yet
Francis: Nope
Me: can you?
Francis: sure...why?
Me: i can't find the multiple twinning in Chloritoid anywhere! It's sposed to be really clear but I can't find it. Can you?
Francis: Did you flip down the polaroid lense.
Me:..........Ohhhh! I'm an idiot
Most of you who read this blog are no doubt, confused and not amused. I'll explain. See, I'd like to think of myself as actually quite good at mineral identifications. Multiple twinning happens frequently on a mineral called Plagioclase and it looks stripey, but only under polarised light. Me, looking at the stupid mineral in plain light, saw nothing but this...
Of coarse you can't see multiple twinning under plain light! You need to polarise it so it looks like this...
This is something I should have known... and this is why for 10 minutes after I was laughing and banging my head on the desk!...
Things picked up from there though. Soon after that to my surprise, my brain started working again...Huzzah!
Nathan, the Tutor only proving my brain was working...
Me to Nathan: Is there such thing as Chrinoidal Limestone?
Nathan to me: Yes there is!
*Whoot!*
Me to Francis: No. There's no Hornblend. It's all biotite, the extinction angle is zero. There does seem to be some discolouration caused by chemical alteration in the biotite though.
Nathan to Francis: It's biotite. It's been partially altered to form chlorite.
*Whoot!*
Me to Alex: I think it's biotite. It may have just been smudged though. That would explain the wacky birefringance!
Nathan to Alex: No! It's not Biotite. It's a mineral we haven't encountered yet!
*Well, 2/3 isn't too bad...Whoot anyway!*
Later I was amused to find that Alex's pencil case which is one of those ones you can slide letters into to spell your name, did not actually say Alex on it. It said John. Supposedly that is it's name. That was funny enough without Francis pointing out the fine print to me above and below the name John!
I am a pencil case
Hello my name is
JOHN!
My owner is a lovely girl named ALEX!
Well... that was my bizarre Geology lesson!
CU Soon!
posted by Amanda at 8:55 pm
1 Comments:
I love how no one dares comment on the nerdy post...except the nerd! OK... I'll stop talking to myself now...!...
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