Lemons and lemonade

People always say "life gives you lemons? make lemonade."

Of course, science is full of these opportunities. Just yesterday I got given one.

This is how barite (BaSO4) separation usually works for me:
1. I attack the samples with a bunch of different acids at room temperature, some bleach at 80 degrees C, a little AlCl3, and ash at 700C, and - poof! BaSO4 powder is left.

However, that's on open ocean sediments, where there really isn't that much terrestrial material.

Working in the Gulf of Aqaba, which essentially serves as a natural dust trap for several different deserts, is a whole different story.

After conducting a similar procedure, I'm still left with tons of dolomite crystals, clay particles, and some other terrestrial, "indissolvable" materials.

Normally, people dissolve this with some hot HF + HNO3 and - poof! Dissolution! However... this also dissolves the BaSO4 crystals, which I need in tact...

So, I've sieved my samples through a 20um filter, am putting all of this (>20um and <20um fraction) through a warm, 1N acetic acid dissolution in a sonicating bath to attack the dolostones (I walk upstairs to shake them regularly too). Then, later today, I got to take a look at what's left in each fraction.

A bright, white oval BaSO4 crystal?

Another BaSO4 crystal?

A bunch of terrestrial junk...

Now, I'll get the "opportunity" to characterize the Ba-isotopic composition of an "indissolvable, >20um terrestrial fraction." So... one extra data point and a learning opportunity.

#science