Here is some fluorite (purple) and calcite (yellow) on sphalerite (silver). No further comments, I just thought this was pretty.
Stalactites and stalagmites form in caves when water that contains dissolved minerals (such as calcium carbonate) drips from the ceiling. Scientists can analyze the 18O/16O ratios (isotopes of oxygen) in the stalactites and see how the temperature changed as they were formed. A team led by Andy Baker, Gurinder Nagra, and Pauline C. Treble of the University of New South Wales, Australia discovered that Yonderup Cave had a lot more 18O than they expected. Since having more 18O is associated with higher temperatures at the time of formation, it could have been interpreded as one of the largest climate changes in the last 2 million years.
But, there was a wildfire in 2005 and a large tree died right on top of the cave. Baker’s team believes that this is what actually caused the increased 18O concentration. This is important for anybody else trying to use these oxygen isotopes to determine ancient temperatures, because if they get a very warm result it might have been caused by a forest fire instead.
It’s a little more complicated than that. Read the whole article here: http://cen.acs.org/articles/94/i30/Cave-dripwater-contain-fire-evidence.html and check Baker’s website for more interesting stuff about how he researches caves to learn about past climates.
A while ago, we went over to Mr. and Mrs. Snow’s house and learned how to make cabs. Dan provided the equipment and Connie provided a delicious lunch and took photos so I would have something to write about. Everyone had a lot of fun.
In this economy, we all could use some career advice. Here is an interview with a former curator of the Denver Museum of Nature and Science, explaining how he got the job and what it entails. (more…)
At Mark Sherwood’s talk “Earth Science… Facts, Frauds and Scams” he mentioned carborundum (also spelled carborundrum). It is made of silicon carbide, but it is not a natural mineral that you can find in the ground. If you want to find some carborundum, look in a chimney. At an iron foundry, the carbon and silicon in the smoke rise and precipitate on the inside of the chimney. When the chimney is cleaned, they find these nice silicon carbide deposits. They are iridescent and pretty enough to buy, but don’t be fooled. Some sellers will say that carborundrum or moissanite and pretend like it is from some secret mine or even a meteorite, but it is really a man-made mineral.
Note: Moissanite is a naturally occurring silicon carbide, but it is very rare and it doesn’t look like the specimen pictured above. It actually looks like tiny green glass crystals. They are usually heat treated to increase clarity. If so, the seller needs to disclose that the specimen has been heated or they are being fraudulent. Buyer beware.
The Spring 2017 Gem and Mineral Show was very successful. The parking lot was filled to capacity and we made over $3000 for the scholarship fund. I think it helped that it was so cold on Saturday, because people wanted to do something indoors. Here are some of the highlights.
We hope you are having fun at the show. Don’t forget to set your clocks forward 1 hour for Daylight Savings Time.
Lectures presented by the Association of Earth Science Clubs of Greater Kansas City
Friday, March 10, 2017
3:00 p.m. “Opal Down Under”, Ron Wooly, Owner of Dreaming Down Under
Saturday, March 11, 2017
1:00 p.m. “Earth Science… Facts, Frauds and Scams”, Mark Sherwood, Independence Gem and Mineral Society
2:00 p.m. “The Life and Hard Times of the KU T. rex”, Dr. David Burnham, Research Associate, University of Kansas, Lawrence, Kansas
3:00 p.m. “Medullary bone in Tyrannosaurs: a question of chickens, eggs and possibly more”, Dr. Josh Schmerge, University of Kansas, Lawrence, Kansas
4:00 p.m. “History of Gold Mining”, Doug Foster, Show-Me Gold, Missouri
Sunday, March 12, 2017
2:00 p.m. “The Life and Hard Times of the KU T-rex”, Dr. David Burnham, Research Associate, University of Kansas, Lawrence, Kansas
3:00 p.m. “Islands in the sun: Eocene fossil mammals from Turkey”, Dr. Chris Beard, University of Kansas, Lawrence, Kansas
The Association has a scholarship for students studying earth science. The value will be between $250 – $1000. To apply, fill out this form on the Association website here and mail it to Molly Stinemetz. The application says 2015 but it is good for 2017. The scholarship happens every year.
Deadline: February 28, 2017
- Be a student at an accredited college or university in Missouri or Kansas
- Must have completed your sophomore year, or be a grad student
- Major in a field related to earth science
- Be a legal resident of the United States
- Complete the application honestly and on time
- Include a recommendation from a professor
- Include a transcript
- If you are selected as a finalist, you must attend the auction at the Kansas City Gem Show on Saturday, March 11, 2017 at 7:15pm.
When you come to the show, don’t forget to enter the drawings for door prizes.