Thursday, June 4, 2020

Sandstone for Complete Dummies

red sandstone
Red sandstone; color from an iron-rich cement
We try not to point out the abject stupidity of anonymous netizens very often (by our count, less than 0.1% of the time so far) but every once in a while we find content so remarkably clueless that we feel compelled to honor the anonymous donor with a DotD nomination, So without further ado, let's have a look at what some onetime "eHow Hobbies, Games, and Toys Editor" (now identified only as "Contributor") foisted on the public in a Sciencing.com post titled, "How to Identify Sandstone."

First things first... let's look at the definition of sandstone: it's a sedimentary rock composed mainly of sand-sized particles. There is a specific definition of "sand-sized" (116 mm to 2mm in diameter). There is a more general definition of "mainly," but for our purposes we can say that sand-sized particles comprise more than 50% by volume. Note that there is no reference to the mineralogy, color, or any other physical attribute of the rock, only its grain size.
According to anonymous, however,
"The sand grains are usually in the 0.1 mm to 0.2 mm range and made of quartz."
Anonymous got the size wrong and made the oft-repeated, yet mistaken claim that sand = quartz. It does not! Our "contributor" also claimed, among other statements, that,
  • "It typically registers 7 on the Mohr hardness scale" – Sandstone does not have a defined hardness. Oh, and the name of the hardness scale is Mohs with an s (and no apostrophe, thank you).
  • "It is usually tan or yellow from the mixture of the clear quartz and feldspar, which is dark amber."  – Does this putz really think feldspar is "dark amber"? Sheesh. That's not to mention that color is often a result of the cement (see above)
  • "...irregularly-shaped patterns with wavy layers indicate deposits from sand dunes while more regular layering indicates deposits from water." – Bullshit. 
  • "...sand... usually settles out of suspension. " – No, it doesn't, regardless of what Wikipedia says. Only the finest sand fraction is carried in suspension, the bulk is moved by traction.
Well, look at that: we didn't even have to wake up the staff geologist to debunk the bushwa our Dumbass of the Day was trying to spread!
copyright © 2020-2021 scmrak

SI - SEDIMENTOLOGY

2 comments:

Max said...

Hi, I stumbled on your blog when searching instructions for a DIY project. I appreciate you trying to correct the info. Although, your time might be better spent trying to address the problem at its root - the crappy sites that are allowed to post these things. Rather than attacking the writers who are often lower income and are just hustling to get by. The internet is full of worse things than these articles.

Steven Mrak said...

We appreciate your forbearance in not calling us "bullies," Max. While we heartily agree that there are worse things on the internet, we lack the wherewithal to silence Bulgarian 'bots or a certain Twitter-maniac. That being said, if you follow the "sites" link at the top of the page to the list of HomeSteady.com posts, you might get the impression that our work here is accomplishing something, since Leaf Group has deleted hundreds of the posts we've featured.

We must, however, disagree with you that we should lay off the writers because they are "lower income." When did poverty become an excuse for dishonesty? It's quite clear that our "nominees" knew they had no idea what they were writing about, and just wanted the moolah. The freelancers who did write in an area where they had expertise don't end up here.

Whatever the case, thank you for stopping by,