# Gallstones and Kidney Stones on the Mohs Scale of Hardness **URL:** \ **Category:** Factual Questions\ **Created:** [April 26, 2014, 2:34pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054 "2014-04-26T14:34:18Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [April 26, 2014, 2:34pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/1 "2014-04-26T14:34:18Z")
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? ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [April 26, 2014, 2:46pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/2 "2014-04-26T14:46:56Z")
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. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [April 26, 2014, 4:11pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/3 "2014-04-26T16:11:04Z")
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. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [April 26, 2014, 5:59pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/4 "2014-04-26T17:59:25Z")
Most kidney stones tend to be somewhat friable, and can break up in passage through the urinary tract. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [April 26, 2014, 9:50pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/5 "2014-04-26T21:50:59Z")
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. ---
**Author:** ![Rysdad](https://avatars.discourse-cdn.com/v4/letter/r/7cd45c/32.png) [@Rysdad](https://boards.straightdope.com/u/Rysdad)\ **Post date:** [April 27, 2014, 5:37am UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/6 "2014-04-27T05:37:50Z")
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. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [April 27, 2014, 11:10am UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/7 "2014-04-27T11:10:08Z")
Got it: [Gallstones, C-14, and atmospheric nuclear tests](http://www.ncbi.nlm.nih.gov/pubmed/3960079). ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [April 27, 2014, 5:10pm UTC](https://boards.straightdope.com/t/gallstones-and-kidney-stones-on-the-mohs-scale-of-hardness/687054/8 "2014-04-27T17:10:33Z")
Cool.