Talk:Silicon dioxide

message: Can you please tell me why I would find Silicon dioxide in the ingredients list on a packet of food and how safe is it to consume?
I second this --Plonk420 22:09, 19 Apr 2005 (UTC)
replies: text: I was also looking it up to see why it is used in food, but found no answer. I noticed it's the last ingredient in Nestea iced tea mix, and that can't be for "crunchiness" since liqueds aren't normally crunchy. 76.64.156.168 (talk) 23:18, 20 July 2008 (UTC)

text: silicon Dioxide is used in the making of bread, made and baked in Wal-Mart Stores in the Northeast US. The bread ingredients label
says "& Not more than 2% Silicon Dioxide added (as an anti-caking agent)" It also appears again in the same list saying "Not more than 2% each of Calcim Silicate & Silicon Dioxide added (as an anti-caking agent)"
74.67.65.212 (talk) 18:06, 07 Dec 2008 (UTC)
thread_title: Silicon dioxide in food

message: Silica is now being used in motorcycle tire manufacturing. It makes the tires more compliant and temperature stable. This lets manufacturers make tires that grip better and still handle loads, without excessive wear from higher temperatures. It also affects wet weather traction.
2601:8:AA00:2DC:CD6:966F:8156:F87B (talk) 03:30, 23 April 2015 (UTC)
thread_title: Use in tires

message: Please outline some of the basic reactions that silica gel is likely to undergo, especially those relating to the preparation of the products listed in the page. could you also include a method for purifying the silica source into the final silica product.
Please come to my job and do it for me so I can stay at home and throw food at my wall.  —Preceding unsigned comment added by 192.198.151.130 (talk) 10:45, 21 February 2008 (UTC)
thread_title: Reactions of silica

message: Isn't it a good thing to have silica in shampoo? But what does it do in it? 71.250.17.62 02:20, 17 June 2006 (UTC)
thread_title:  Silica in shampoo 

message: As far as I know there is no free silicon in nature, but silicon is in oxidized form; in silicon dioxide (quartz etc.) or in complex oxides with metals (silicates). So there is little to happen (chemically) for silicon in a fire or in a lightning. I removed the fires and strokes of lightning producing silicon dioxide(and fulgurites added there afterwards). --AB-fi 18:29, 11 July 2006 (UTC)
replies: text: It was badly written. I meant to say that silicon dioxide could be formed naturally from silicates by some high temperature processes. I apologise for lack of thought and poor proof reading. The section is now much improved compared to the time when my sentences were added. Jaraalbe 21:43, 11 July 2006 (UTC)
thread_title:  Chemistry 

message: Does this material turn into glass when heated? C'uzz i have no idea.
Technically you can as normal sand is used to make glass and sand is mostly made Ou of silicon dioxide Lolcat64 (talk) 04:06, 18 April 2020 (UTC)
thread_title:  ? 

message: The Journal of Nutrition, Health, and Aging Vol 11(2) 2007 has a special symposium including an editorial and five articles on emerging data with respect to the health benefits of silica.  According to articles, silica is the second most prevalent element after oxygen.  Articles refer to compelling data suggesting that silica is essential for health.
:Here's a nice summary of medical uses/benefits of silica. Don't know how trustworthy the site is, although it does cite some legitimate sources. If anyone is in the mood of adding this info to the page, please do so. Aurimas 06:44, 12 September 2007 (UTC)
thread_title:  silica health benefits 

message: What's supposed to be linked at the MSDS link in the info box? Donald Hosek 23:45, 25 June 2007 (UTC)
thread_title:  MSDS? 

message: I see that a mention of use in bottled water has been removed following this revision. I'm not sure why it was removed, but I know for sure that silicon dioxide can be found in mineral water (at least the one I drink - Naleczowianka), and it's listed under Mineral Content, so it's probably somewhat significant. 36 mg/L of SiO2 in the mentioned mineral water. I will revert back to the older edit and add additional info if no one minds. Aurimas 08:11, 12 September 2007 (UTC)
replies: text: Just noticed that it's in fact an undo by Scarian of the previous revision. Any reason why this was removed? Manufactured forms is probably not a good place to put it, I agree. Maybe there's a need to start a new section regarding SiO2 in foods? The first comment on this page already hints at a need for this section. Aurimas 08:17, 12 September 2007 (UTC)
replies: text:  silica is also a selling point of Fiji brand bottled water. Among other claims, the label says "it provides the water's great mouth feel" 97.82.247.200 00:37, 20 September 2007 (UTC)
thread_title:  Bottled water 

message: You'd think that it being the most common compound in the crust would make it notable.
Although I'm not really sure of this. Can anyone confirm this?-=Elfin=-341 04:31, 4 October 2007 (UTC)
replies: text: Actual SiO2 is not as common as that table might suggest (60%); that's a simplified way of expressing all silicon compounds, including a large variety of silicates. To make the point more obvious, note that the table says there is 3% of "Na2O". This represents again many sodium minerals, but in this case there is no pure Na2O at all, since it is very reactive (it is a very strong base). --Itub (talk) 13:21, 21 February 2008 (UTC)
thread_title:  SiO<sub>2</sub> Most common in crust? 

message: another name for sioSubscript text is silicon dioxide,silica, or silox they are there scientific names  —Preceding unsigned comment added by 98.21.93.105 (talk) 01:06, 15 March 2008 (UTC)
thread_title:  another name for SiO<sub>Subscript text</sub> 

message: "Inhaling finely divided crystalline silica dust in very small quantities (OSHA allows 0.1mg/m3) over time can lead to silicosis, bronchitis or (much more rarely) cancer, ..."
Does this mean:
*"Inhaling finely divided crystalline silica dust in very small quantities over time can lead to silicosis, bronchitis or (much more rarely) cancer, ... but the OSHA defines a limit of 0.1mg/m3 below which the risk is minimal.";
*"Inhaling finely divided crystalline silica dust in very small quantities over time can lead to silicosis, bronchitis or (much more rarely) cancer, ..., even if exposure is below the OSHA 0.1mg/m3 limit.";
—? Cutler (talk) 09:50, 21 April 2008 (UTC)
thread_title:  Ambiguous statement 

message: I came to this article to find out how safe it is to ingest food (or drugs) that have silica as an ingredient.  (This applies to a large number of especially drugs, and I just purchased for the first time a diet drink -- in powdered form -- with silica as an ingredient.)
My only concern was that the silica particles might be jagged and irritate my digestive tract.  Sure enough, the article confirms this potential hazard:
"Small pieces of silicon dioxide are equally harmless, as long as they are not large enough to mechanically obstruct the GI tract, or jagged enough to lacerate its lining."
Thing is, this powdered product might have been pulverized by people blissfully unaware of what their processing might be doing to the shape of the silica particles, and I'd like to know this is not a risk before using it.
Does anyone have an idea whether jagged silica particles is is a realistic danger for food or drugs that are manufactured with silica as an ingredient?  
If so, this would be well worth mentioning in the article.
P.S.  Someone asked about the purpose of using silica as an ingredient in food products.  My guess is that it has nothing to do with making the product "crunchy" (or if it did, we'd know that jagged silica particles is a real possibility!).  Rather, I suspect it's used just as it is in silica gel packets: to keep the powder from becoming moist. (And therefore avoid clumping.)Daqu (talk) 01:00, 6 September 2008 (UTC)
thread_title: How safe is ingesting silica in food???

message: Silox is often used as a shorthand name for (t-butyl)3SiO. It is  the name of an industrial group. Is it also a name for silica? --Axiosaurus (talk) 09:02, 23 October 2008 (UTC)
replies: text: It appears to be used by some for silicon dioxide deposited from a vapor, Chemical vapor deposition (CVD), in preparing semiconductor devices e.g. . Mikenorton (talk) 09:21, 23 October 2008 (UTC)
replies: text: In fact it appears to be derived from a trademark of Applied Materials Inc. for their low temperature vapor silica deposition process. In this interview if you're interested .Mikenorton (talk) 09:38, 23 October 2008 (UTC)

text: thanks for that- the ref seems to refer to the process e.g. CVD at atmospheric pressure using (presumably) the trademarked process/equipment, but I have not read the paper just the abstract. IMO silox is a very specific usage and a name used for the passivating oxide film on silicon created using the silox process,  and because of the ambiguity with the tert-butyl compound and the fact it is a trademark putting it in the lede with the specious derivation of silox from silex (I would bet that it came from silicon oxide)is questionable.--Axiosaurus (talk) 10:17, 23 October 2008 (UTC)
replies: text: Removed. BTW I think that silex is in there to explain the origin of 'silica'. Mikenorton (talk) 10:37, 23 October 2008 (UTC)
thread_title:  Silox- is this really a name for silica? 

message: :Moved here from article as conflicts with other references (also secondary) which give 1470 as a transition temperature- --Axiosaurus (talk) 10:20, 11 December 2008 (UTC)
thread_title:  Melting point of cristobalite 

message: Hi
Can any one tell me if I can use the sand in my fishpond filter  —Preceding unsigned comment added by 41.30.241.103 (talk) 06:24, 25 April 2009 (UTC)
replies: text:  It should not be a problem, as the stuff is chemically inert. The main issue would be the particle size distribution desired for the specific application. Beach sand is fairly coarse grained, in general. -- logger9 (talk) 17:11, 22 October 2009 (UTC)
thread_title:  silica sand 

message: Can anyone please tel me whether SiO2 is acidic, basic or amphoteric?  —Preceding unsigned comment added by Vigneshmanix (talk • contribs) 13:56, 25 November 2009 (UTC)
replies: text: It is definitely acidic under Lux-Flood definition. --Cubbi (talk) 15:34, 26 November 2009 (UTC)
thread_title:  Acidic, Basic or Amphoteric? 

message: * http://scholar.google.com.hk/scholar?as_q=silicon+dioxide+food&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_sdt=1.&as_sdtp=on&as_sdts=5&hl=en
--58.38.41.98 (talk) 05:55, 10 April 2010 (UTC)
thread_title:  Info about the chemical as a food additive 

message: I hope i'm not embarrassingly wrong but on checking I think there has been a misunderstanding of how to interpret the SiO2 stoichiometry:
In each of the most thermodynamically stable crystalline forms of silica, on average, only 2 out of 4 of each the vertices (or oxygen atoms) of the SiO4 tetrahedra are shared with others, yielding the net chemical formula: SiO2.[4]
This is entirely wrong as far as I know. In SiO2 all oxygens must be shared between two Si atoms to achieve the stoichiometry. Each O bonded to two Si atoms is effectively makes up 1/2 if we were base SiO2 on the smallest repeating unit, hence all 4 are crosslinked. I've made the appropriate changes anyway- i'm merely commenting on here to draw to attention if i'm wrong.  —Preceding unsigned comment added by 131.111.243.37 (talk) 22:12, 22 May 2010 (UTC)
thread_title:  Stoichiometry 

message: In the introduction, there is a random plug for silica nanosprings. It is out of place in the general context of the introduction and seems to be for nothing more than to promote a group's work. Recommend deletion. 99.255.24.249 (talk) 06:23, 1 February 2011 (UTC)
replies: text: Indeed. Removed. Materialscientist (talk) 06:27, 1 February 2011 (UTC)
thread_title: Springs

message: alpha-quartz is listed as s.g.#152, whereas
http://cst-www.nrl.navy.mil/lattice/spcgrp/trigonal.html#sg154
says its #154. I don't have access to literature to check at the moment, can anybody confirm? Thanks.
12.104.156.31 (talk) 00:27, 17 December 2011 (UTC)
replies: text: A superficial answer: No. 152 is P3121  ; No. 154 is P3221. These groups are very similar and both assigned to the same form of quartz . (different "enantiomorphs" - "left" and "right" alpha quartz) Materialscientist (talk) 00:51, 17 December 2011 (UTC)
thread_title:  space group number 

message: What is molten silicon dioxide's density at melting point? This info should be in the article. UNIT A4B1 (talk) 22:09, 25 April 2012 (UTC)
replies: text: Melting point depends on the crystalline form. I've added a note above the table for 1950-2200 C. Materialscientist (talk) 07:21, 26 April 2012 (UTC)
thread_title:  liquid density 

message: This picture shows 4 oxygens!!!! it needs to show 2. (Unless I missed the point of this picture!) Creeper jack1 (talk) 19:13, 1 February 2013 (UTC)
thread_title:  The Picture on the left near the top 

message: The passage on solubility is confusing, as it says that silica is more soluble than quartz.  But elsewhere it is said (correctly) that quartz is a form (in fact, one of the most common forms) of silica.  So presumably what is meant is that some other forms of silica are more soluble than quartz, in which case it would be useful to sya which they are.109.158.46.214 (talk) 22:13, 12 April 2013 (UTC)
thread_title:  Solubility 

message: It is stated that silicon dioxide (silica) is a primary ingredient in industrial Portland cement.  Is there a source for this?  As I understand it Portland cement is manufactured from limestone (calcium carbonate), clay minerals, and gypsum (in that order).  If available, a limestone already containing a suitable proportion of clay minerals is used; otherwise, clay is added to the mixture.  I am not aware that silica in free form (e.g. sand) is ever added to the mixture. (Of course, silica sand is usually part of the aggregate used in concrete, but not the cement itself.) Clay minerals themselves are complex aluminum-silicate compounds, so I suppose you could say that they contain silica, but I don't think silica would usually be recognisable as a distinct component.109.158.46.214 (talk) 22:33, 12 April 2013 (UTC)
replies: text: Portland cement and ceramics in general is an area where our editing crew is technically weak, so your comments are helpful.  The main gluing stuff of cement is the clinker, which consists of calcium silicates derived from various clays (aluminosilicates) and lime (calcium oxide source).  Other comments or corrections would be very welcome.--Smokefoot (talk) 03:22, 13 April 2013 (UTC)
thread_title:  Portland cement 

message: In the section "Uses", paragraph 4, it is stated that silica is an insulator, but also that it stores electrical charge.  
To store charge for electrical use requires both an insulator and conductors to form a capacitor, so is the statement correct ?   
An explanation would be appropriate please, any offers ?    Darkman101 (talk) 07:54, 20 September 2013 (UTC)
thread_title:  Contradiction ? 

message: Hello, here the Jmol interactive 3D Image is irrelevant, because it represents the SiO2 diatomic molecule, not any of the crystalline forms of silica. Do we have the correct one?
Nicola.Manini (talk) 17:33, 17 December 2015 (UTC)
replies: text: Smokefoot removed the  input, and the Jmol link is using that input so now Jmol is gone too. -DePiep (talk) 19:58, 17 December 2015 (UTC)
thread_title:  jmol interactive 3D Image 

message: Substituted at 06:11, 30 April 2016 (UTC)
thread_title: Assessment comment

message: The Plate tectonics article mentions in passing that silica and water form a deep eutectic system. Does some elaboration belong here? I have also placed a similar comment at the talk page at eutectic system. —Theodore Kloba (☎) 14:14, 20 September 2017 (UTC)
replies: text: Possibly in the Geology section, sure. Be Bold and make any changes you seem fit. Polyamorph (talk) 09:38, 20 April 2018 (UTC)
thread_title:  Silica + Water Eutectic? 

message: "as a function of temperature, it peaks around 340 °C.[49]" [49]=http://www.minsocam.org/ammin/AM62/AM62_1052.pdf which states "The solubility of amorphous silica at the vapor pressure of the solution, from 0° to 250° C, is given by the equation log C = -731/T + 4.52, where C is the silica concentration in mg/kg and T is absolute temperature. The maximum solubility at the vapor pressure of solution is 1660 mg/kg at 340°C, and the extrapolated solubility at the critical point is 890 mg/kg. At a constant pressure of 1034 bars, the solubility of amorphous silica from 0° to °C is given by the equation log C = -8102 + 4.82."
As it says, that is the "maximum solubility at the vapor pressure". The equation is in regards to the vapor pressure. If you look at the data they got the max solubility is actually between 4000 and 7000 PPM (4 g/L and 7 g/L): http://www.minsocam.org/msa/AmMin/Supplemental_Data/Vol%2062%20p1052%20AM-77-051.pdf (mentioned in [49] as "AM-77-051"). --User123o987name (talk) 14:56, 25 March 2020 (UTC)
thread_title:  Misinterpretation maybe 

message: In the polymorphism section, with the caption "Typical subunit for low pressure silicon dioxide", the diagram is completely wrong. The silicons at the bottom of the "pyramid", so to speak, are connected by oxygens. This should not be the case. Each silicon should bond tetrahedrally, with the Si-O bonds pointing downwards from the Si, and then presumably going off the edge of the diagram. Silicons should not be bonded to other silicons on the same layer of the crystal structure. As it is, the depicted molecule cannot form a crystal structure. Humanoid-human-5 (talk) 04:55, 10 January 2023 (UTC)
replies: text: I am willing to help, but first you need to try to explain the problem, without ranting.  
*"the diagram is completely wrong." completely?
*"The silicons at the bottom of the "pyramid", so to speak, are connected by oxygens. " that aspect is completely correct.
*"Each silicon should bond tetrahedrally" as is shown.
I think that you are trying to say that individual Si4O10 cages are not found in low pressure forms of silicon dioxide? --Smokefoot (talk) 13:59, 10 January 2023 (UTC)

text: Basically in the diagram you can see that the individual Si-O-Si bonds form the edges of a tetrahedron. However, it's the molecular shape around each individual silicon that should form a tetrahedron, with the oxygens being the vertices. In the diagram the silicons are the vertices and there is nothing in the middle. As you say, the "cage" should not be found in low-pressure silicon dioxide. Humanoid-human-5 (talk) 00:33, 19 January 2023 (UTC)
replies: text: I can clearly see silicon centered tetrahedra with bridging oxygen atoms in the figure you refer to. Polyamorph (talk) 12:49, 19 January 2023 (UTC)
thread_title:  Wrong diagram 

message: silica(Silicon dioxide-SO2) 119.93.39.194 (talk) 01:21, 19 May 2023 (UTC)
thread_title:  Science Grade 9