Coaldale Crater Gemstones, Meteorite Impact Produces Rare Specimens Options

[ASTROBLEME]

CP,

That angular white inclusion that swizz noticed in your pics also caught my eye. It appears to be a fragmented calcium-aluminum-rich inclusion. There is a substantial amount of very detailed scientific research published about CAIs but a quick explanation is found here;

CAIs

I'm certainly looking forward to getting these polished stones under my microscope.

Thank you for a job well done!

ASTROBLEME

Another great question for the extended study on these Chris....I'm not sure on those white-ish inclusions you mentioned but there is one with right angles on the same rectangle stone shown in pic 2 reversed. Should be quite interesting finds I believe. Hopefully Johnny has a much better magnification and photography set up than I do too.

[swizz]

Referring again to the meteorite specimens in the first image (finished cabs)... the smaller of the two circular cabs in particular. If you enlarge the image, that one appears to have a yellowish inclusion unless that's the light playing tricks. I don't see that on the other pieces. Also suspected CAI?
Thank you for that CAI link Johnny.

[Denise]

The cabochons turned out great Dan, nice work.

[CP]

Thanks Denise, they were fun to cut and are all very unique to work with for sure. Thanks for the link too Johnny, interesting.

Just remembered today gathering up everything for the trip back to Johnny and further study too.....the saw cutting samples and thinner slices ..... so glad to have taken the time and been able to recover some clean samples of that for the continued study as well! I'm excited as all git' out to find out what's waiting to unfold before our eyes almost literally!
I sure don't have the equipment or knowledge to do further tests, but I'm proud to be able to do the small part I can to help further the study with the samples collected during cutting.

[ASTROBLEME]

Thanks to CP's expert cutting and polishing efforts, it is now much easier to observe the features within the meteorite specimens.

Here's a microscope photo I've taken of the surface on one of the finished gems. The image reveals planar fracturing of the blue-green colored inclusion along with the melt pocket rim that was formed around it by gradational thermal alteration. This evidence is consistent with hyper-velocity impact events.

The beauty of these gemstones surpasses anything I've ever encountered in meteorite specimens. They are truly a work of art. Thank you CP!

Sincerely,

ASTROBLEME

[CP]

Thanks again Johnny, I'm really glad they all turned out so well too!

After cutting those meteorites I'm in complete agreement with Johnny on the high velocity impact influence upon them. As someone who's cut literally hundreds of pounds of agate from volcanic deposits, I can say for certain these were unlike any of those. The inclusions (chrondite/chrondules) were mostly fractured (with had melt pocket rims) in this way Johnny has illustrated, but in a volcanic sedimentary agate/nodule one might expect or find some fractures closer to surfaces possibly from freezing, weathering etc....then in a bit deeper the cut nodules/agates would likely be unbroken further within. Also the matrix hardness for the body of the piece seemed softer than what a typical agate or cryptocrystalline quartz forms in from volcanic flows/sediments and would be expected in my experiences while cutting or polishing.

Very much look forward to hearing what else Johnny has to tell us as time progresses with his work too! Kudo's Johnny, super cool stuff you're working with and I'm honored to have helped a little bit as a cutter.

[ASTROBLEME]

LUNAR METEORITE CREATED COALDALE CRATER!

A certified laboratory analysis of the material left over from CP’s gemstone prep is finally in hand and I’m sharing some of that research with you as I had promised. It is now my understanding, in consideration of the following;

1. Geology of the suspected impact crater structure at Coaldale
2. The minerology of the sample
3. Shock lamella and melt rims visible in sample
4. Values for elements in lab analysis being cross referenced with lunar samples

... that a very large impact into the moon ejected a mass having sufficient size and velocity that it ultimately formed a crater near Coaldale, Colorado USA. The most easily recognized pattern for determination of meteorites from the moon is by testing for an “Eu anomaly” in the specimen. The analysis I have secured displays such a deviation. Please reference the attached file for the data.



You can learn much more about the most recent lunar science that I used to formulate my opinion at this link…
Free Lunar Research Paper

Sincerely,

ASTROBLEME

[GeoMatt]

Extrusive rocks associated with volcanism in Colorado also have a documented negative Eu anomaly. Potassic trachybasalts (and other similar rocks) associated with this geographic area (both Rio Grande, and 39 Mile Volcanics), which share some affinities with your samples (high % phenocrysts, some enrichment of light REEs, etc., visual similarities), have a known negative Eu anomaly. I don't see a correlation in your element charting that can't be more readily explained by the local geologic history.

I'm not saying what you have isn't what you think it is, but that there are other explanations for the rock characteristics that have to be excluded. Just like melt rims, reaction rims, zoned crystals, etc.. on phenocrysts of volcanic rocks are not uncommon. As well as slickensides associated with faulting.

I note that you also state the mineralogy as a defining characteristic... I didn't see any detailed mineralogy in the previous posts. Have you had this sectioned and examined visually by a qualified mineralogist? microprobe? other method? What was so definitive about the mineralogy that aided in ascribing the given petrogenesis?

I fully understand you are still in process here, so I'm curious to see what else you come up with. Right now though, it wouldn't make it through peer review.

[ASTROBLEME]

GeoMatt,

Thanks for your comments. I do have additional analyses that I compared against representative samples of the local volcanic deposits. No correlation was found.

A lunar meteorite expert is assisting with this matter.

Sincerely,

ASTROBLEME

[ASTROBLEME]

Dear Colorado Prospector Members and Visitors,

The Eu anomaly graph I posted earlier was meant to be an informational tool for use by prospectors but I now realize that some additional information may be needed to assist others wanting to learn more about this matter.

Here is some data from my certified laboratory analysis that I plotted onto the graph of the peer review literature recommended for interested parties to read. I hope this will help you better understand the relationship of the present research efforts at the Coaldale Crater discovery to the Apollo moon mission sampling efforts conducted decades ago.

Sincerely,

ASTROBLEME

[GeoMatt]

The plot on the figure suggests your sample has limited correlation to that dataset. You would be looking for correlation within that plot (although correlation does not make a lunar rock), as terrestrial samples could plot all across that chart. Do you have a Mo and Nd values to plot up against other samples? - the ratio of those elements seems to be a little more definitive in assigning terrestrial vs. lunar origin. I would assume you have K and U values as well, as they can provide further indication of lunar vs. terrestrial origins (K/U vs K).

[swizz]

You guys are waaay over my head now but please keep us posted Johnny, I'm extremely interested and following.

[ASTROBLEME]

Everyone,

I've compared my data against NASA lunar sample files, peer review papers, Clementine and Lunar Orbiter data...and it correlates quite well.

Let's take a look at actual lunar meteorite data since my opinion is based on a large meteorite being ejected from the moon. The chart that I've attached depicts my data against a well known and respected lunar meteorite institution's publication. I'm pleased to give credit to the Department of Earth and Planetary Sciences at Washington University in St. Louis for their base-line graph data. The chart shows the locations for collecting the lunar meteorites along with their scandium and samarium composition as compared to my data that is depicted in red.

ASTROBLEME

[GeoMatt]

Actually, if you look at the source page for the chart you've used above for scandium vs. samarium (http://meteorites.wustl.edu/lunar/chemclass/feo_th_all.htm), you'll see some text at the top of that page that you may want to acknowledge. Quoted here:

Lunar meteorites span a wide range of compositions, a range that far exceeds that of meteorites from any other parent body. The charts below are useful for distinguishing different lunar meteorites from EACH OTHER. They are not particularly useful for distinguishing lunar meteorites from terrestrial rocks.

The stressing of "each other" is theirs, not mine.

Perhaps maybe plot your ratios for some of the compounds I've listed previously, or SiO2 vs Fe2O3 +MgO as WUStl suggests as diagnostic. Something where there is obvious division between lunar and terrestrial sources.

[ASTROBLEME]

Hi Everyone,

I have long recognized that all prospectors share the same passion but not the same scientific backgrounds. It has always been my goal to help everyone, regardless of skills, to find what they are searching for. At this point, I don't think further charts or spreadsheets would help those served by this club. There are many other websites that deal in the data driven research for those that seek such knowledge. This post should help those following this thread with understanding what has been discovered.

Coaldale specimens have glass inclusions that are exotic. A small lunar meteorite was collected in Northwest Africa a couple of years ago that has glass clasts, a gray colored fine grained matrix and has a chemistry that is remarkably similar to Coaldale.



The scientific paper was published a few months ago and can be downloaded for free at this link;

Lunar Meteorite NWA 10404

Sincerely,

Astrobleme