Where would gallstones (specifically, removed from a human, if it matters) and kidney stones (similarly) rank on the Mohs Scale of Mineral Hardness?
Slightly-related question: if a patient is having his/her gallbladder removed, and had a weird desire to keep the gallstones as souvenirs, could he bring a jar to the hospital with him and ask the doc to save them for him? Or does this run afoul of medical waste disposal protocols?
There are different types of kidney stones. Calcium oxalate (the kind I am prone to) rate a 4 on the Mohs scale (according to wikipedia). Struvite stones are around 1.5 to 2.
There are different types of gallstones too. I got mine in a jar without asking. It was simply on the table by my bed. I still have it. Gallstones can be mostly cholesterol, whilst pigment stones contain bilirubin and calcium salts. Cholesterol stones are not very hard and fragment easily. I have heard of people having pigment stones drilled and threaded onto a necklace.
Most kidney stones tend to be somewhat friable, and can break up in passage through the urinary tract.
Totally off topic, but years ago, when the question was asked, “just how long does it take for a gallstone to grow inside somebody”, the way that the answer was determined was very clever.
As I recall, the various layers of gallstones were assayed for their Carbon-14 content, recognizing that atmospheric nuclear tests had led to a rapid and characteristic pattern of Carbon-14 enrichment of the atmosphere starting in the early 1950’s. Likewise, as such tests became less frequent and eventually ceased, there was also a known pattern of decline in atmospheric C-14 later on (I think in the 1970’s).
Regardless of the specifics, the point was that Carbon-14 concentrations in the various layers of a gallstone could be compared to the well known and unmistakeable pattern of atmospheric C-14 concentration that occurred following WWII as a result of nuclear testing. And, in that way, the chronology (the dendochronology?) of the gallstone established. The result was something like a 15 year span of gradual accumulation.
I will dig around for a reference.
My ex-wife asked for and got her gall stones in a little jar. I’d guess that the doctor sent a couple off to pathology beforehand, though.
Cool.