Astimex

[Kristian Drivenes]

Thanks for the feedback, guys. Rob, I'll be in touch

[DavidAdams]

Hi all,
I would like to introduce myself. 
I am Rob Croucher, the business manager here at Micro-Analysis Consultants Limited (MAC) and I would be more than happy to help with alternative standards to those that were previously supplied by 2SPI and Astimex.

www.micro-analysis.com

Hi Rob and everyone,

I just got a custom block from MAC a few months back and the quality of the product I got was really amazing. It was WAAAAAAAY better than the one that Malcolm pointed out that I got from ASTIMEX during my time at UWA. Just wanted to put that plug out there

Dave

[Mindshadow]

Thank you Dave and sorry for the late response.
I had turned off notifications by mistake 

Great to hear that the standard exceeded expectations (the cheque is in the post  )
We continually strive to improve so feedback both positive and negative is appreciated. 

As a side question.  Does anybody have any contact information for anyone at Astimex as we may be interested in purchasing some or all of their materials.
I have searched everywhere I can think off online but found nothing.

[Ben Buse]

Just looking at MAC Albite standard https://micro-analysis.com/materials/material.asp?id=375

Element    WT%
K    0.72%
Ca    1.17%
Na    9.37%
Al    12.54%
Si    34.58%
O    41.62%

How was it analysed? And how do you get 9.37 wt.% when maximum for ideal formula NaAlSi3O8 would be 8.767. Similarly how do you get 34.58 wt% Si when ideal NaAlSi3O8 would be 32.13, ok bit of Ca and bit of K substitution but this shouldn't increase Si. Do MAC need to do a round-robin supplying standards to labs for analysis? And how do you get O of 41.62?

[Ben Buse]

Similarly how do they get these values for calcite  https://micro-analysis.com/materials/material.asp?id=415
Element   WT%
Ca   42.53%
C   17.25%
O   40.21%
Compound   WT%
CO2   52.31%
CaO   47.69%

When stochiometric calcite is Ca 40.044, O 47.956, C 12

[Probeman]

Similarly how do they get these values for calcite  https://micro-analysis.com/materials/material.asp?id=415
Element    WT%
Ca    42.53%
C    17.25%
O    40.21%
Compound    WT%
CO2    52.31%
CaO    47.69%

When stochiometric calcite is Ca 40.044, O 47.956, C 12

My guess (and it's not completely a guess) is that they're using standardless EDS. 

It would be far better to simply assume stoichiometry on end member compounds such as these, minus what traces you can measure on the probe.

All the more reason for a global set of high purity synthetic mineral standards:

https://smf.probesoftware.com/index.php?topic=1415.0

Or we can stay in the 17th century where we compare our results:

"by Standards kept by each particular workman, without any agreement or reference to one another"
-Edmond Halley, 1693