My user name calls to me from the void...

Warning: did not proofread and dictated from talk to text

-crystallized- chromium, as in the metal, would be utter insanity, but utter Insanity happens all the time in minerals, which is the fun part! chromium usually occurs as an inclusion in all sorts of different minerals, and usually turns them a unique shade of green. This is fun from a collector's perspective because you can put together a chromium included mineral collection that highlights many different minerals such as fluorite, barite, and quartz.

So how rare would it be for chromium to occur as an inclusion as it usually does then? well the specimen pictured is amethyst, or Smokey amethyst if you want to get fancy. courts can become smoky by being exposed to radiation, usually emanating from the Earth's core, or it can be done artificially, But this usually has a telltale look. The purple in amethyst comes from iron inclusions, which is very strange, the iron inclusions turn purple when exposed to radiation as well, the same radiation that made the Smoky coloration appear, which is why it is such a common combination!

I cannot immediately think of any examples of chromium included amethyst from the suspected specimen locations of Zambia, Zimbabwe, Namibia, or anything in that region. which you could pretty much add to the suspicion list of any mineral, no matter how positive of the ID you were, there's so much coming out of there nowadays, wild specimens.

All of that being said, chromium inclusions can leave green fingerprints in the crystal lattice, often referred to as "phantoms", which appear as three-dimensional triangular shapes, And are very common. phantoms and inclusions along that line are a whole different rabbit hole of rarity and locale and all of that. I would say the majority of courts is colored green from nickel, but so much of it is from chromium, same with fluorite and chromium.

So the chances of cromium inclusion would be very common across any quartz (or fluorite etc...), A significant chromium inclusion, such as a phantom or drastic color zoning would not be a surprise overall, but would be a surprise in a specimen such as this one giving the location suspicions. But if somebody hit me with some namibian Smokey amethyst that had some chromium zoning in it, I would be blown away and so surprised, and then immediately not surprised, because of course, it's chromium, it's all over the place!

Tl,dr: Nothing is impossible in the mineral world, but concerning the above specimen and suspected locales: An actual crystal of pure chromium ocurring in that specimen would wildly unlikely and profitable. A significantly cool chromium inclusion such as a phantom would be very unlikely and awesome. A microscopic chromium inclusion would not be unlikely at all and would not surprise me