MGX Minerals Inc MGXMF

DETECTING COBALT - POLARIZED LIGHT

[Wangotango67]

Few more interesting topics
detecting the cobalt in magnesium carbonate ores...
Photos in link below.

(Mg,Co)CO3 form elongate and prismatic crystals with hexagonal cross sections. At up to 1 mm in length, such crystals are the largest and the most noticeable occurrence of (Mg,Co)CO3, which also occurs as inclusions <5 microns across.

These inclusions typically consist of magnesian spherocobaltite and kolwezite (Fig. 3). These are common in supergene chalcocite and create the characteristic texture visible in Figure 3. Their pink color distinguishes the Co-bearing from other rhombohedral carbonates (Fig. 3). In hand samples of cobaltoan carbonates, the color is intense even in specimens with less than 5 wt.% Co.

In dolomites and calcites the pink tinge is much subtler in thin section, where all but the most Co-rich crystals are only pale pink in plane-polarized light and look no different from ordinary dolomites and calcites with the polars crossed. By contrast, spherocobaltite and compositions along the join towards magnesite retain their intense pink color in thin section. Even in crosspolarized light they have a rosy cast. This intensity of color, and the lack of effervescence even in powdered specimens, distinguishes members of the magnesitespherocobaltite solid solution from the cobaltoan dolomites.

All the Co-carbonates are uniaxial, optically negative, and highly birefringent (maximum δ = 0.18).



Shorter version - same author -
Main link for full article ( in former post ) is in this edition also  - outlines as (full link ) 

CHECK OUT THE PHOTOS -  UNDER  PLAIN  POLARIZED  LIGHT

- hand specimen - clearly shows the cobalt in the magnesium carbonates.

.

https://www.geo.arizona.edu/publication/mineralogy-geochemistry-and-metallurgy-cobalt-rhombohedral-carbonates


What i'm gathering here is...
This dolomite cobalt is indicative to some copper deposits. 
Carbonate Cobalt formations sit atop.

Which doesn't nessisarily mean the magnesium carbonate with cobalt has a relation to the copper deposit below .

Does this central b.c. cordillera have copper ?
Yes.... all the way up and down.

Were sandstones mentioned in tech reports ?
Yes....

And if most know their geology... central b.c. was most likely a watershed throughway.
Going right into the states all the way down to Nevada. if one researhes the Cariboo region, there's significant silts andxlays still present - central isle.

If there's a good water push headed southerly...
It would be understandable there would be sandstone deposits creates... 
With most likely lots of caerboantes.

It's not inconcievable to think, an overlying calcium or magnesium carbonate ore body - already thought of as, replacement, could overlye another depsoit - and the overlye having nothing t odo with what's below a far deeper depths. hence, merging, or replacement.

Influx of seismic activity from the platonci western plates = pushed up the cordillera into mountai nranges. Hence, carbonate deposits atop of mountains.

My other thoughts are....?
If the pinks are associated to the cobalt species in magnesite carbonates...
Then... could the purple descriptive ores - be associated to the sulphide cobalt s in irons ?
Ahhhhh.....

If there wt oere cobalt present in the magnesium carbonates - not saying there is- but suppose it was so...

I would say....
the cobalt has an argillite + iron + copper = association ( purple cobslt )
And... upon blending with the magnesium carbonate -  or - dolomite - the strong acids in calcium turns the cobalt - pink.   Tw oforms of cobalt - purple - pink hues.

Calcite is mentioned in the report.
- Calcium. ( form of  calcite )



Cheers...

excuse the typos...
I think i've worn out another lap top - keys are not responding.
Hope my investemnts pan out... i've gone thorugh several tablets computers and lap tops.
Too costly to keep buyign them.