(After long gap previous 2018-10-22.)

cobalt pigment

(MK2) was supernatant (light blue) of fusion and dissolution (MK1) of cobalt pigment + NaOH, done on 2018-09-14.  Currently it became a clear supernatant + dark olive ppt. 

Filtering by gravity:
* (MK2p) olive-black ppt
* (Mk2q) clear white liq (may contain xNa2O.ySiO2) slightly olive smoky.

(MK3) was supernat (clear white) of (MK1). Now clear liq with long crystals (Na2CO3?) +some black powder ppt.

Decanted the liq from (MK3) -- clear, sly olive smoky, viscous -- to(MK3q)

Crystals (MK3p) washed with a bit of EtOH 46%.

With acid, (MK3p) everfesced, but left a white ppt (SiO2?)

(MK13) and (MK13a): mass of wet crystals, white, semi-opaque. With HCl, it bubbles but leaves behind a small amt of crystalline opaque solid.

Merged (MK13a) (MK3p) into (MK13). Dried on petri over warm heat; left mass of white crystals.   Added ~70 mL EtOH 96%.
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Discarded (MK2a) (MK3a) from watchglass.

Old (MK1b): clear, with a bitof ocher ppt.

New (MK15): clear liq with brown-ocher ppt.

Merged (MK1b) and (MK15); filtered:
* (MK20) clear liq.
* (MK21) brown ocher ppt; probably Fe more than Co.

(MK1d) (was (MK1) + H2O + Na2S2O5 + HCl): pink-tangerine liq + white ppt.  Pipeted out supernat (~5 mL?) to (MK17). Resuspended the ppt with some H2O.
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