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Heavy liquids


#1

I am trying to set together my own heavy liquids.

I found suppliers for Methylene iodide, Bromoform and
monobromonapthalene.

I have two questions:

  1. Do I need other liquids?

  2. Bromoform seems to have a s.g. of 2.63 (instead of 2.88).
    There is a stabilized version with s.g. 2.9, but that is so
    expensive that I doubt that is used by the kits you can buy.

Best regards,
Alain


#2
   I found suppliers for Methylene iodide, Bromoform and
monobromonapthalene. 
    1. Do I need other liquids? 

Only if you need a lower SG. monobromonapthalene’s SG is around 1.49
and is used to dilute the others. Benzyl Benzoate’s SG is 1.11 and
is also used to dilute the others. You may also want to make a
saturated salt solution for testing amber. Dissolve as much salt as
you can into a cup of hot water, then pour it off into a sealed
container. SG of this solution is 1.13, and amber will float in it.

    2. Bromoform seems to have a s.g. of 2.63 (instead of 2.88).
There is a stabilized version with s.g. 2.9, but that is so
expensive that I doubt that is used by the kits you can buy. 

Your Methylene Iodide already has a stable SG of 3.32. Diluting it
with the Benzyl Benzoate will yield and intermediate SG you may
need. You can calibrate your liquids by using “calibration stones”.
Some recommended liquid SGs with calibration stones aRe:

2.57…Microcline Feldspar (2.56) float, Chalcedony (2.60) for
sinker.
2.62…Chaledony (2.60) float, Quartz (2.66) for sinker
2.67…Emerald (synthetic is fine) (2.66) float, Calcite (2.70) for
sinker
3.05…Pink Tourmaline (3.04) float, Green Tourmaline (3.06) for
sinker
3.32…(straight Methylene Iodide) Jadeite for sinker. Also,
nephrite will float in this.

Put your sinkers and floaters in the container you wish to
calibrate. Cover them with a liquid that is heavier than what you
want to end up with (usually Methylene Iodide). Then, using an
eyedropper, add the lighter liquid (usually Benzyl Benzoate), slowly
until the lighter calibration stone floats. If you add too much,
just add some more MI.

Just keep in mind that heavily included stones may have a
significantly higher/lower SG than listed for that mineral. Have
fun, I sure did!

James in SoFl, where it is finally raining and the brush fires are
more under control.


#3

Undiluted di-iodomethane (methilene iodide) has an SG approximately
3.33, diluting it with mono-bromonaphthaline you get 2.65 and 3.05
which are helpful for many gemstone testing.

Di-iodomethane has also a RI of 1.74 which can be helpful for
comparing the RI of the gemstones with the fluid’s.

These heavy liquids are toxic and should be used with great care.
Sodium polytungstate may be used, it is colourless cryatalline
powder which can be dissolved in water and it is not toxic. Solution
may give an SG approximately 2.65 and 3.05, maximum 3.10.

Kind regards from Turkey,
Oya Borahan
www.birdamlasu.com