# Is anything else on earth ever more pure than semiconductor grade silicon ? **URL:** \ **Category:** Factual Questions\ **Created:** [June 27, 2014, 3:53pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786 "2014-06-27T15:53:15Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [June 27, 2014, 3:53pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/1 "2014-06-27T15:53:15Z")
I’ve heard that often the silicon used in semiconductors has 11N purity i.e. 99.999…9 (Eleven 9s after the decimal). Is there significant amount of any other element or compound that has been purified to even higher purities ? For me significant amount means \>10g. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [June 27, 2014, 4:09pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/2 "2014-06-27T16:09:25Z")
How pure is the water in the big underground tanks that hold neutrino /exotic particle detectors? ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [June 27, 2014, 4:20pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/3 "2014-06-27T16:20:36Z")
How pure are the highest gem grade diamonds? ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [June 27, 2014, 4:41pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/4 "2014-06-27T16:41:05Z")
Gold in some coins gets four decimal places, and people really care about gold. I’d say silicone is the purest. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2014, 4:54pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/5 "2014-06-27T16:54:52Z")
Any single atom of anything is by definition pure. I think we need to specify how much of a substance qualifies. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [June 27, 2014, 4:55pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/6 "2014-06-27T16:55:51Z")
> [@Mangetout](#): > > Any single atom of anything is by definition pure. I think we need to specify how much of a substance qualifies. Over 10 grams. See OP. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [June 27, 2014, 5:04pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/7 "2014-06-27T17:04:20Z")
> [@The\_Second\_Stone](#): > > Gold in some coins gets four decimal places, and people really care about gold. I’d say silicone is the purest. [Silicon,](http://en.wikipedia.org/wiki/Silicon) not [silicone.](http://en.wikipedia.org/wiki/Silicone) Unless you think goop sold in a tube at Home Depot is eleven 9s pure. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [June 27, 2014, 5:10pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/8 "2014-06-27T17:10:23Z")
> [@Mangetout](#): > > I think we need to specify how much of a substance qualifies. In order to possibly have a purity greater than 99.99999999999% (but less than unity), you’d need a sample composed of more than 10,000,000,000,000 atoms/molecules (although this is far less than the 10-gram limit imposed by the OP). ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [June 27, 2014, 5:20pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/9 "2014-06-27T17:20:07Z")
> [@dolphinboy](#): > > How pure are the highest gem grade diamonds? Diamonds are mostly formed by kimberlites and have significant amounts of non-carbon elements in them. Synthetic diamonds usually also contain impurities (on purpose), such as nitrogen for yellow. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [June 27, 2014, 5:40pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/10 "2014-06-27T17:40:34Z")
My hatred for the New York Yankees. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [June 27, 2014, 6:02pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/11 "2014-06-27T18:02:20Z")
> [@Machine\_Elf](#): > > In order to possibly have a purity greater than 99.99999999999% (but less than unity), you’d need a sample composed of more than 10,000,000,000,000 atoms/molecules (although this is far less than the 10-gram limit imposed by the OP). Sure, but saying that’s far less than the 10g limit is a bit of an understatement. If I remember old Avacado’s number right, it’s smaller by a factor of something like 10,000,000,000 (depending on what it is). And does ‘11 N purity’ mean eleven nines after the decimal in 99.99[…]9%, or eleven nines total (including the two before the decimal when written as a percentage)? ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [June 27, 2014, 6:03pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/12 "2014-06-27T18:03:40Z")
> [@KneadToKnow](#): > > My hatred for the New York Yankees. +1 ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [June 27, 2014, 6:12pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/13 "2014-06-27T18:12:25Z")
> [@Quercus](#): > > Sure, but saying that’s far less than the 10g limit is a bit of an understatement. If I remember old Avacado’s number right, it’s smaller by a factor of something like 10,000,000,000 (depending on what it is). True. If 6.02 X 10[sup]23[/sup] atoms of silicon weighs 28 grams, then 10[sup]13[/sup] atoms will only weigh 465 picograms. > [@](#): > > And does ‘11 N purity’ mean eleven nines after the decimal in 99.99[…]9%, or eleven nines total (including the two before the decimal when written as a percentage)? [Nine (purity)](http://en.wikipedia.org/wiki/Nine_(purity)) the number of nines is apparently the total number of nines in the entire percentage figure, including digits on both sides of the decimal. Something that is 99% pure is two nines pure; something that is 99.9% pure is three nines pure. A related question: Once they have purified the silicon, how do they measure its purity? ---
**Author:** ![Deeg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/deeg/32/2955_2.png) [@Deeg](https://boards.straightdope.com/u/Deeg)\ **Post date:** [June 27, 2014, 6:13pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/14 "2014-06-27T18:13:44Z")
> [@KneadToKnow](#): > > My hatred for the New York Yankees. I was going to say “my innocence” but I like your answer better. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [June 27, 2014, 6:14pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/15 "2014-06-27T18:14:01Z")
A quick search finds vendors selling ultrapure water systems with claims that residual metals are below 1.0 ppt, which would be 9-Ns purity, if I understand things right. Of course there might be some other contaminants, bringing the overall purity level down a bit, but we’re seeing a ballpark anyway. This is a more or less off-the-shelf kind of product; I don’t know if specialized applications with custom hardware might get more pure. Though in some ways this isn’t different from the OP example: evidently the big customers for ultrapure water are silicon chip fabricators. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [June 27, 2014, 6:19pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/16 "2014-06-27T18:19:20Z")
How about fluorine? Or, more accurately, a cylinder of compressed fluorine? Fluorine is so reactive that it will react with any impurity leaving the rest as pure fluorine. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [June 27, 2014, 6:25pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/17 "2014-06-27T18:25:01Z")
> [@Machine\_Elf](#): > > Once they have purified the silicon, how do they measure its purity? Possibly they do have some such means, but it’s possible that they just reverse engineer the number based on the methodology they use. For example, if I mix even parts alcohol and water, I can tell you that it’s half alcohol. If I then mix half this mixture with an even part of water, I can tell you that it’s 1/4th alcohol. This method will continue to proceed down to 1/8th, 1/16th, 1/32nd, 1/64th, etc. If they’re confident of their methodology and know what the percentile of change is per step/time, they can use math to determine the level of purity, rather than testing. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [June 27, 2014, 7:12pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/18 "2014-06-27T19:12:01Z")
> [@Quartz](#): > > How about fluorine? Or, more accurately, a cylinder of compressed fluorine? Fluorine is so reactive that it will react with any impurity leaving the rest as pure fluorine. Chemically reacting with something does not make the atoms that composed that something disappear. If X dissolves any Y that is around, your X becomes more contaminated with Y, not less so. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [June 27, 2014, 9:16pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/19 "2014-06-27T21:16:19Z")
I imagine that fairly soon, graphene will be produced in “large” quantities. That’s pure carbon rings connected to each other. Otherwise, it’s not graphene. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2014, 9:34pm UTC](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786/20 "2014-06-27T21:34:05Z")
> [@ZenBeam](#): > > Over 10 grams. See OP. Completely missed that. Sorry :smack: [Next page](https://boards.straightdope.com/t/is-anything-else-on-earth-ever-more-pure-than-semiconductor-grade-silicon/691786.md?page=2)