Iron, IAB-MG
TKW 30 metric tons. Observed fall: no. Impacted about 50,000 years ago. Found 1891 in Coconino County, Arizona, USA, between Flagstaff and Winslow.
   
Scott writes:
Meteor Crater AZ, "Nininger Star" with iron-nickel spheroids in epoxy on aluminum substrate
17 grams, 80x75x2.3mm
Harvey Nininger, known as the “father of Meteoritics”, did extensive studies of Meteor Crater in Arizona. Wikipedia writes:
Nininger's extensive sampling and fieldwork in the 1930s and 40s contributed significantly to the scientific community's acceptance of the idea that Meteor Crater formed by the impact of an asteroid. In 1942, Harvey Nininger moved his home and business from Denver to the Meteor Crater Observatory, located near the turn-off for Meteor Crater on Route 66. He renamed the building the "American Meteorite Museum" and published a number of meteorite and Meteor Crater-related books from the location. He also conducted a wide range of research at the crater, discovering impactite, iron-nickel spherules related to the impact and vaporization of the asteroid.
Details on the Canyon Diablo iron-nickel spheroids themselves are nicely covered in MPOD postings by Arlene Schlazer (MPOD 8/24/12) and Jeff Kuykens (MPOD 6/5/13).
In the late 1940’s and early 1950’s, Nininger had a deal with a local hotel chain in Arizona to make decorative stars. He embedded the Canyon Diablo spheroids he collected in epoxy resin and deposited them on aluminum that had been cut into star shapes. He then sanded the surface to expose fresh metal of the spheroids, giving the stars their “shine”. The deal apparently fell apart and Nininger ended up giving away some of the stars to friends and others were sold in his museum gift shop. Reports differ, but it seems that somewhere between "less than 100" and "only 400" of the stars were hand-made by Nininger, in three different sizes (3”, 4.5”, 6”), most with five points and a few rare six-pointers.
There are about 80-100 spherules per square centimeter, so Nininger had to have collected an amazing quantity of spheroids to make so many stars!
Pic 1: Front
Pic 2: Back of the star showing the aluminum substrate and some residual "glue"
Pic 3: Front showing scale
Pic 4: Close up of one of the points
Pic 5: 20X enlargement showing the details of the embedded spheroids. I’m amazed at how fresh the metal still looks today after about 7 decades. This photo was taken with a Moment 10X macro lens clipped the 2X lens of an iPhone 14 Pro Max. The lens has only a millimeter or so of focal depth, but then that suffices for slices!
Pic 6: Rob Wesel’s amazing collection of Nininger stars that includes all five known types (3” 5-point, 4.5” 5-point, 6” 5-point, 3” 6-point, and 4.5” 6-point)
I’d like to acknowledge Rob Wesel for his help in acquiring one of these rare and historical objects, and for sharing his knowledge of their history.
Pictures are copyrighted by Scott McGregor, except for #3 and #6, which are copyrighted by Rob Wesel. Pictures may be used with attribution. |