NWA 11577 is an IAB iron that fits into the rare subgroup of IAB-sHL. As a matter of pure numbers the sHL subgroup accounts for only 19 specimens of the many iron metoerites that have been formally classified. Of those 19 specimen, 7 specimens are larger than 1kg, and the rest (much like 11577) weigh in at rather paltry low TKWs that are below 500g in most cases.
It can be tricky buying NWA irons. The nomads and merchants there are not as familiar with irons as they are with stony meteorites, and often On two occasions I have tried to get NWA irons classified before this one, and those stories ended poorly for nearly everyone involved. I’ll spare you the details in this setting though. Pain in the neck… 😉
Anyhow, NWA 11577 was originally an 86g specimen found by Nomads in Algeria in Decmember of 2016. A portion of it was cut off by the merchant and sent to Tony Irving who confirmed that it was a meteorite. After that confirmation I arranged to buy the main mass from the Moroccan merchant who sent that type specimen to Irving. Having worked with Tony multiple times myself, I arranged to have him send the small piece he had to Chris Herd at Univ. of Alberta, who subsequently classified this for me.
The sHL subgroup is an interesting one. If you look at the list of specimens classified as such, and peruse though some of the images of their Widmanstatten patterns, you’ll see quite a variety of patterns pop up in this subtype. They vary from anything between tight, very small Widmanstatten patterns which you need a loupe to really appreciate, too more distinctive patterns like the one you see here.
I have a special place in my heart for iron meteorites, though I tend to prefer the historic variety with a bit more story behind them. Rare classifications are interesting, but I know other people will appreciate this meteorite more so I’m offering up all the available specimens of this now. Once these sell out I have nothing to offer someone who comes a little late to the game…