@vickyveritas I voted for #Goethite. I've got a soft spot for it since my wife did a bunch of XRD on goethite as an undergrad researcher #mincup23

#LRT come on vote for #goethite! Don't upset the limpets! :blobcateyes: #MinCup23

#Goethite versus #Topaz today for #MinCup23.

On that one I'm voting topaz, because of the versatility in colors, that basal cleavage and also because I offered one to my wife as an engagement ring.

Goethite, there's indeed the pigment use argument and the pseudomorphology... But no. Topaz it is.

Vote here! https://www.mineralcup.org/2023/campaigns/round-1-match-6

limpet teeth, a composite containing #goethite, are the strongest known biological material in tension -twice as strong as spider silk.
#MinCup23 #Limpet #Minerals #Materials
https://daily.jstor.org/worlds-strongest-material-limpet-teeth/

Rumney, R.M.H., Robson, S.C., Kao, A.P. et al. Biomimetic generation of the strongest known biomaterial found in limpet tooth. Nat Commun 13, 3753 (2022). https://doi.org/10.1038/s41467-022-31139-0
Open Access
https://www.nature.com/articles/s41467-022-31139-0

Repost of Cormac McGinley's photo of limpet feeding tracks, cut by #goethite teeth.
#MinCup23

https://fosstodon.org/@Cormac_McGinley@mastodon.sdf.org/111000777265914932

Okay, so looks like neither is very chaotic this round - #topaz is primarily used for pretty-shinies (and do we blame them? No), and #goethite is *bog iron*, y'all.

However! I'm voting goethite and lemme tell you why: 1) it has a cool habit of coming in after other minerals and taking over where they were, crystal shape and all! (Okay a lot of opportunistic minerals do this, but I think it's cool every time.)

(I've got more reasons, hang on, hitting char limit.) #MinCup23

Oooo #topaz vs #goethite. Iirc topaz is fairly inert on the chaos scale... but I don't remember what goethite is off hand.

Lemme get comfy and I'll get into it...

(It's probably worth noting that I'm just a nerdy amateur rock collector that likes to collect safely, not a geologist or mineralogist or anything of the sort. So I use basic sources, because I can more or less understand them lmfao. When I'm wrong, tho, pls feel free to kindly teach otherwise!) #MinCup23

Limpet (Patella sp.) feeding trails - the one in the centre was clearly eating on the go! It's trail reminds me of a bungee rope.
Limpet teeth are made up of fibers of Goethite - one of the strongest known natural substances. County Clare, Ireland.

Cormacscoast.com Walking tours

#wildatlanticway #walkingtours #discoverireland #keepdiscovering #marinelife #biodiversity #Limpet #limpetfeedingtrail #goethite #Ireland

A dense layered mix (from top to bottom) of dark red bubbly #goethite, silver crystalline #arsenopyrite, golden yellow #chalcopyrite and lighter red country rock with minor clusters of green #chlorite throughout. Fossicked from #minewaste at Wheal Fortune (Great Consolidated Mines), Gwennap, #Cornwall.

This is a typical mix of Cornish mining minerals. You don't want to drop this one on your toe, it's really heavy for it's size.

mindat.org minID: LXJ-DP6
specimen size: 75 mm x 50 mm x 40 mm

#Fluorine mouchetéE de #Goethite de Chaillacn en Indre. Mine fermée en 1997, une des plus grosses production de barytine (ou baryte), minerai du Baryum d'Europe https://mamot.fr/media/jI_bZpob2JQr3dQxamY