I'll admit, this story is creepy.
A sophomore opens a roll of quarters she's had for months, and out comes a crumbly white powder. She's cognizant of this not being a normal thing, calls the authorities and after laboratory assessment, the result is apparently ricin, an exceptionally toxic biological compound.
This is creepy for more than one reason. First, ricin has natural origins in the castor bean, but you can't just go out and buy it -- which is a good thing. Ricin was known to be toxic since the late 1800s and was developed into a weapon by the US during WW II but never used. The most famous person killed by ricin poisoning was Georgi Markov, a Bulgarian dissident killed in London in 1978 by Bulgarian secret police using a 1.5mm platnium pellet injected into his leg with a modified umbrella. The pellet contained an estimated 500 micrograms (half a gram, barely enough to see) of ricin toxin, and killed him within three days of injection. On a dose basis, ricin is roughly 30x more toxic than VX nerve gas, which is one of the things we wish we could un-invent -- and unlike VX and cyanide and many other nasty things, there really isn't a good treatment for ricin. If you get enough of it, you'll die, and there's not much modern medicine can do. It's a cellular poison, it stops protein synthesis and since protein synthesis is pretty much what your cells are about if you stop that the cells die.
A crumbly powder isn't a really effective means of distributing ricin, there is some suggestion that the humidity Austin is famous for worked to this young lady's advantage, because it's even more deadly inhaled than injected or ingested. A dirty little secret that works in favor of those of us in the civilian population when it comes to biological warfare is that it's really hard to make a powder that will float in the air like a mist. When you make particles small enough to be inhaled, they'll typically clump together due to static electricity. Overcoming the static problem is what separates the pros from the wannabes in biological terror, which is one of the reasons the anthrax from 2001 was a real threat and this particular ricin trick is far less of a threat.
Using money to spread a biological agent works better for infectious agents than for toxins. The first mention of this I remember was in Frank Herbert's book The White Plague, a book I do not recommend, Herbert produced one work of unparalleled genius in the form of Dune and promptly jumped the shark. Money is a good means to spread disease, your momma was right when she told you to not put that in your mouth, but even touching contaminated coins and touching your eye is enough to expose you to highly infectious diseases like influenza. In this case, if the powder didn't aerosolize when the roll was opened, you'd have to ingest the powder, and even an Aggie wouldn't eat the white stuff that came out of a roll of quarters. Aggies are too tough to be killed by anything so pedantic as poison, but they wouldn't eat it anyway.
My first thought is that this is not really ricin, and more laboratory testing will show that in the next week. If this is ricin, given what we know it's most likely the product of some loner crank along the lines of the as-yet-unapprehended Tylenol cyanide poisoner from the 1980s. The presence of this compound at a university suggests the typical greasy-grad-student-with-grievance scenario, I imagine the young lady at the center of the investigation will be contact-traced by the FBI back to her first-grade teacher in an effort to find a suspect. The roll of quarters is a unique method of distribution and if inserted at the bank level it would imply a wider conspiracy aimed at random people -- if the UT chick isn't the primary target but a random bystander intended to cover the death of another, a review of other people who died precipitously with fever in the last several months in central Texas would be in order.
The object lesson, at this point, is don't put money in your mouth, especially if it has white powder on it. We will await further developments.