Total Pageviews

Tuesday, February 25, 2014

Barite or Baryte: A View from Cobachi, Sonora, Mexico

          Barite (spelled baryte everywhere besides the U.S) is a heavy, non-magnetic mineral with very high specific gravity of up to 4.5. It is one dense, soft rock. Barite (BaSO4) is useful in the manufacture of paper and rubber, as a tracking agent in medical tests in  the human body, and as the weighting material put into drilling fluid to keep the sides of petroleum drilling casings from collapsing and to prevent blowouts. It is readily used down boreholes as it does not interfere with any magnetic tests associated with drilling. The pinkish crystals pictured below are barite. The darker, smaller mineral is cerussite. The radiating form of barite crystals is sometimes referred to as Bologna Stone (for the town in Italy, not the lunch meat):

              The most useful variety for petroleum geologists occurs as thick sedimentary beds of pure barite with little to no silica impurities. Barite often occurs interbedded or interfingering with chert, so pure beds of thick (a meter or more) barite are highly prized:

            Pure barite needs little jigging (essentially shaking the rock in an aqueous solution), washing, heavy media separation, tabling, or flotation to be used down well bores. The barite is merely crushed to a uniform size and put in the drilling mud. 77 percent of barite is used for this purpose. And even though it is a heavy mineral, it is considered non-toxic due to its high insolubility. Deep oceanic BaSO4 deposits are useful in constraining the temperatures of oceanic crust in paleoenvironments.

            Barite in the form of desert roses is also coveted by rock hounds:

             My remarkable six-month, first adventure out of college included mapping a barite deposit in Cobachi, Sonora, Mexico. I lived with two British geologists, Rod and Kevin, and a geologist from North Carolina, Phyllis, in the little white house in the left of the photograph:

           The house had no windows, doors, or running water...but it was just $100 a month to rent. :-) Cobachi is so small (about 300-350 people) that it often does not show up on maps, even in our GPS age (though it does here):

                Mapping the barite deposit including making a grid through the desert (with the help of a local crew of ten men with machetes), scaring cows off the runway so the small plane could land, performing specific density tests, stratigraphy and paleontology including late Paleozoic fusulinids, and learning Spanish. We also hiked to the top of Sierra Cobachi with our friends from the community. They carried thick, heavy Coke bottles up and down the mountain to this stunning cave:


          This image of the people in Cobachi reminds me of how warm and kind they were to us very foreign-looking and sounding geologists. We would be treated to tomatoes on our burritos when they could afford none for their own families. They taught us to make tortillas and goat cheese and withstood us asking the same questions countless times as we learned Spanish. We took part in dances, loud wailing funerals, and evening talks about our day's adventures.

           Anaconda Barite just announced they will be upgrading the jigging plant in Cobachi early this year. So the heavy mineral barite (named from the Greek word heavy) will provide more years of economic opportunities to Cobachians. Here's hoping the heavy Coke-bottle carrying is no longer going on, though :-).

           Cobachi surely holds a heavy place in my a good way.

           Any early career adventures you'd like to share? Or your own favorite barite story?

Sedimentally yours,

Word Woman (Scientific Steph)



  1. Big spike in Partial Ellipsis of the Sun caramel dioxide blog post viewing this week. Do you suppose someone is considering using it in fracking ;-)?

  2. SS,
    If some fracking entrepreneurs use caramel dioxide in their mining operations they would be morally, if not legally, obliged to cut you and your kindergartners in on the profits… Could be a sweet deal!

    Love the desert rose bouquet. I think that’s what Fred sent to Wilma a few weeks back.

    My MW Collegiate Dictionary Tenth Edition has been getting a workout since I started reading PEOTS (that’s a good thing). Cerussite, chert, fusulinids, etc. I may have to invest in a geology dictionary.

    My MW says barite is “barium sulfate occurring as a mineral.” The element barium, is says, is toxic. When you write that barite is used “as a tracking agent in medical tests in the human body” does that relate to medical X-rays of the alimentary canal? The toxic element barium perhaps is different from barium sulfate.

    Why did your friends from Cobachi carry the thick, heavy Coke bottles up and down the mountain? Picnic in the cave? To return them for a deposit? Perhaps a barite deposit?

    “Pure barite needs (a?) little jigging…” The image I get is of a troupe of Riverdanders, all jigging in sync and bearing jugs (a group of Ganymedes?) sloshing with barite crystals in an aqueous solution known as green beer (Greenymead?).

    Speaking of dancing rivers, I imagine that waterways are the setting of many a mineral’s sedimental journey. (I love your “sedimentally yours.” No need this week to add an “i” a la “palimpsestially.”)

    Is the photo of your house in Cobachi reversed? The white house at the left seems to have windows and a door (can’t tell about the running water). (Nice gazebo, though.)

    Sounds like your early-career adventures in Cobachi were memorable. Share my barite stories? Don’t get me started. I have so many wonderful barite tales I could relate that it is impossible to pick a favorite!

    But I do have one wretched barite riddle:
    Q. What did Ganymede have to do whenever Zeus summoned him to bring green nectar (Olympia beer left over from a Riverdance performance) but then made him wait while he threw down a fistful of thunderbolts?
    A. Grin and barite.


    1. There are some exquisite fusulinid cross sections from Cobachi in this article, lego:


  3. Hey Lego,

    That is so bad, it's good. Have to start with that pun and work my way up your column stratigraphically (from the bottom).

    Pure barite does NOT need much jigging, just crushing. That is why it is so prized. The barite used in drilling fluid may have a density of only 4.2, rather than 4.5, so some impurities are allowed.

    I pulled the more recent photo of Cobachi off the Internet as I could not readily find my personal photos yesterday...when I lived there it had door and window openings but no actual wood or glass in them...

    Yes, they carried the Coke bottles for picnics and back for the deposit. Good old agua just wouldn't do.

    Indeed, barium sulfate is used for those gut x-rays. Since it is insoluble in water, though, it is not toxic. Barium is different from barium sulphate. Maybe Jan might expand on this as used in colonoscopies and barium (actually barite) enemas.

    A sweet deal, indeed! I find it interesting that the caramel dioxide post got 43 hits this week. The first fracking post got only 6. We'd love to know what you thought, caramel dioxide fans...


    1. You may also watch a four-minute video from Anaconda Barite showing the process of getting barite from the ground to the barge in Guaymas, the port city to the west.


      It was just a bit shocking to see the pristine landscape all torn up...Great to see all those local workers, though.

  4. I'm in primary care and I don't have a good enough imagination to be a radiologist -- they see things that aren't really there -- so I have little need for barium swallows, enemas, etc. I do refer patients for bariatric surgery; don't think I've had to treat a diver for barotrauma -- same root there. Just keeping an eye on the barometer now, hoping to avoid another snowstorm.

    1. We got a little snow last night but it's mostly gone. Sorry you guys have had such a rough least it's late winter?

      Thanks for the additional bari- and baro- words, jan.

    2. SS,
      Regarding my wretched riddle: I’m just channeling my inner skydiveboy until that lad wises up and latches onto PEOTS and starts posting his preposterous puns!

      Are barium swallows related to barn swallows? And if fledgling attorneys receive barium enemas, do they then have to pass the bar-ium? (I picture SS with a thought-bubble hovering over her head, “Hmmm, what’s the Blogger protocol/procedure for banning a poster from PEOTS?”)

    3. lego, keep 'em coming! I always enjoy a good pun.

      P.S. If you liked "How Its Made," you'll like the barite mining video above...with music! ;-)

    4. SS,
      Loved the video. High production values (both the video and the barite). It was like watching MTV in the 1980s, or maybe GTV (GeologyTV).

      I’m always tickled to see workers indoors, checking out blueprints or sitting at computers, wearing hardhats. I guess Mexico has its own version of OSHA. I guess the woman who just came from the manicurist who was dealing with flasks ands scales must have talked the video director into letting her go hardhatless.

      Regarding “^It’s…”: “It’s Monty Python’s Flying Circus!


    5. So glad you liked the video, Lego. That music is catchy and the hardhats in the office did crack me up.

      Might see if I can work in Monty Python with science and writing for a future post ;-).

  5. And if you are into bigger dinosaur fossils from Madagascar:


    1. SS,
      Thanks for linking the Minneapolis Strib’s Mazda-gas-car (sic) dinosaury story. (In this case, the brand of gas would be Sinclair.) Any news feature that includes the word “Lego” is aces in my book. Does your daughter know Professor Rogers? Take a class from her?

      As for working Monty Python into a future PEOTS post, here is my favorite scene from “MP & the Holy Grail” (and that’s saying something). It’s… got everything -- logic, science (well, pseudo logic and pseudoscience), the Socratic method, sophistry, peasants with a scorch-mob mentality and a grand climactic large-scale experiment.

      Keep up your great work, wisdom and whimsy, Steph (and your insights also, jan and others who have posted legitimately scientifically astute comments here). I learn from you all “who are so wise in the ways of science.”


    2. I think my daughter got lots of geology as a kid so has not taken geology classes from Dr. Curry Rogers. My daughter was identifying mica flakes pretty early on :-).

      Great scene, of course!

    3. Still waiting for Gingrich to get better.

    4. SS and jan,
      To quote the NPR’s “Hadean Zircon Rocks!” story linked below:
      “…an early proto-Earth was melted by a violent impact with a Mars-size object (Really? A puny candy bar is going do all that damage?). The crash created the moon and turned our young planet into a red ball of molten rock. … It would have glowed almost like a star. …”
      To quote (and then paraphrase) Paul Simon’s “Red Rubber Ball”:
      “And I think it’s gonna be all right,
      Yeah, the worst is over,
      But the Sun’s third rock’s still glowing like a red molten ball.”

      Your daughter is already rather geology-savvy? Yeah, I should have known. The pebble falls not far from her maternal rock of granite. Mica flakes? I couldn’t even distinguish between oat flakes and corn flakes until I was about 25.

      (Buy new and improved Life Cereal, now fortified with mica flakes! “{Give it to}Mikey. He won’t eat it. He hates everything. … [chomp, chomp, chomp] He likes it! Hey, Mikey!”)

      Proposed title of Chapter One in your daughter’s eventual autobiography: “A Girl’s Journey from Mica to Macalester”

      Quick riddle:
      Q: What would they call the big game between the Macalester Scotties and Green Bay Packers?
      A: The Mac & Cheese Bowl

      Love the verb “bogart.” Humphrey has the (unique?) distinction of having both a surname and nickname make it into dictionaries as lowercase entries. (Future NPR puzzle?)

      Flick pick: “We’re No Angels” with Aldo Ray, Peter Ustinov and Bogie is a Christmas-spirited gem, definitely not sub par.)

      I contend that if your parents saddle you with a name like Newton, you gotta embrace it, don’t off the “on.” It would be like a kid named Bradford lopping off “dford.” You’re just begging for tittering. The best solution, of course, is to change your bad name to something wonderful like jan, Steph or…

    5. Maybe instead: “A Girl’s Journey from Mica-lister to Macalester”

    6. Her eyeballs, not mine. She once told me that life did not have to be so very EDUCATIONAL all the time!

  6. Big news in geology this week, I see, if by "news" we mean "something that happened 4.4 billion years ago."

    But really, the discovery was made by Jack Valley in the Jack Hills?

    1. And is "Hadean Zircons" a great name for a rock (!) band, or what?

    2. Great find...I was bogarting that article for next week. But, hey, if the dated zircon age is plus or minus 6 million years, plus or minus a week is nothing ;-). . .

      Is your comment implying he does know Jack, jan? ;-)

      "Hadean Zircons" definitely rocks!

    3. Ok, two things I must say about the article:

      The geologic age column showing the oldest at the top is not the way geologists would portray ages in a stratigraphic column. The oldest rocks are always at the bottom and get progressively younger as you go up the column.

      The caption for the blue-colored zircon notes "The color ranges from transparent to red" which is just a tad confusing.

      Both items surprised me in an NPR article.

      I don't think so, but am I just being nit-picky?

    4. Agree on both counts. I used to describe digging through our pre-EHR medical charts as archaeology: the older notes and test results were on the bottom.

    5. Sheesh! Even the New York Daily News and got it right, noting that the transparent to deep red zircon turns blue when bombarded with electrons. Also found it humorous that Dr. Valley is the lead investigator at the University of Wisconsin-Madison.

      Looked through some of the NPR article comments to see if the two issues were commented on, but I gave up after a slew of creationism age comments.

      The most amazing thing to me is that it took only a 100 million years (from 4.5 to 4.4 billion years) for the earth to cool enough to form zircon crystals. That is a mind-blowing idea!

    6. Hey, you read Mario Livio's book -- didn't Lord Kelvin also have a problem with the age of the Earth and the rate of cooling?

    7. Yes, you're right. The earth's age is 50 times what he calculated based on the "laws of physics" at the time. Kelvin also annoyed Lyell and Hutton and other geologists in the process.

    8. No one can be sure they're right all the time, not even sdb. ;-)

    9. Aw, SNAP! (A heat of radioactive decay pun.)

    10. Uranium zirconium hydride fuel puns are some of my favorites!

      RTG on!