Emerald juice

[YT2095]

I boiled roughly 50 grams of raw uncut Emeralds last night in aqua regia.

much of the grey crystaline limestone has dissolved even right down into the inclusions, the Mica schist also comes off now quite easily.

however the aqua regia soln is now a deep gold color almost orange and perfectly clear.

it looks a little like Gold Chloride soln, now I realise this unlikely to be the case, and that the majarity of it will be Calcium salts, but what causes the Gold color?

beryllium nitrate is yellow, and since emeralds contain a lot of beryllium could that be it?

it`ll not be Cr salts, but it May be Vanadium salts, I have no listing for that color in my books though.

 

anyone have any ideas?

[woelen]

Aqua regia becomes yellow/orange after a day of standing, even without anything added to it. When it is heated, this reaction goes much faster and may take only minutes or tens of minutes.

 

HNO3 + 3HCl ---> Cl2 + ONCl + 2H2O

 

The Cl2 is pale green, the ONCl is bright orange, the mix has a golden yellow color. Both gases remain dissolved in solution.

 

Just as a test, take 0.5 ml of conc. HNO3, take 1.5 ml of conc. HCl, and mix. You'll obtain a colorless liquid. Next, heat this mix, without adding anything. Within 5 minutes or so, you will see the yellow/golden color, and the same color of gas mixture above the liquid.

 

=======================================================================

 

if you want to see the pure color of ONCl, then add a spatula of NaNO2 (nitrite, not nitrate) to conc. HCl. The liquid will turn beautifully orange at once:

 

First, the nitrite reacts with the acid in solution:

 

NaNO2 + HCl --> NaCl + HNO2 (the white solid, which does not dissolve is plain salt)

 

Next, nitrosyl chloride is formed: HNO2 + HCl ---> ONCl + H2O

 

Nitrosyl chloride has a beautiful orange color.

[YT2095]

this happened almost instantly though, I added the Nitric 1`st and heated it, there was a reaction, but nothing fantastic, when I added a drop of HCl there was a White cloudy PPT very similar to Silver Chloride, after the rest was added it went yellow and the Emeralds were fizzing quite happily, well, the junk they were set in was fizzing, the emeralds didn`t react at all.

[woelen]

If you added the emeralds to the colorless HCl/HNO3 mix and then it once turns golden yellow, then indeed it is not due to formation of ONCl. Formation of ONCl takes some time, even for the hot liquid it still takes a few minutes.

 

If the color appeared at once, then it must be some impurity from the emeralds. Try to dissolve one in conc. HCl only. Doesn't it give the same effect? The trouble with such things is that the composition of the used materials is so very uncertain. They could contain all kinds of metals. Vanadium can lead to yellow colors for the pervanadyl cation, which certainly is formed under the strongly oxidizing conditions of HCl/HNO3 mix. Iron (III) also leads to yellow colors, due to formation of the tetrachloroferrate (III) complex, but that also happens in plain HCl, without HNO3.

[YT2095]

yup, in plain HCl there is a White cloudy taint and then upon heating it goes yellow as the crystalised limestone fizzes.

[woelen]

This also rules out vanadium. Vanadium in its minerals has oxidation state +4, and that would give blue ions (vanadyl). For the yellow color I only can think of iron impurity, or organic material, which was trapped into the impure mineral. Try adding a mix of red and yellow prussiate of potash. Add just a few tiny crystals of both prussiates to the acid mix and shake to dissolve. If you obtain a blue color at once, then there is iron impurity. You do not need to fear possible formation of HCN, if you only add a few mm³ of solid.

[YT2095]

yup, instant Blue, there`s Definately Iron in there!

 

there is one thing I neglected to mention. when the soln`s cold it`s a light yeallow, when heated it gets Much deeper towards Orange/Gold.

 

edit: I just did the old Zinc and Magnet test also, it`s most definately Iron.

[John Cuthber]

I know you are not going to leach a lot of Be out of emeralds but it's nasty stuff so be careful.

BTW, congratulations on finding the commonest of the transition elements.

[Sayonara]

I boiled roughly 50 grams of raw uncut Emeralds last night in aqua regia.

Out of curiosity, how much does 50g of uncut emerald go for these days?

[insane_alien]

Out of curiosity, how much does 50g of uncut emerald go for these days?

 

10 gold and a +3 sword of pwnage

[YT2095]

the price varies wildly depending on the samples, this should give a rough idea though: http://www.mineralminers.com/html/ememins.stm

[Cesium]

Aside from purchasing it on ebay or the like, are emeralds probably the best, (only?) easily accessible source of beryllium?

[YT2095]

I wouldn`t have thought so no, Beryllium is used in several industries and tools, it`s also alloyed with Copper sometimes too, and used as the raw material in some watch springs.