I was walking along the train tracks (I know, I shouldn’t, but I was) and came across these strange specimens. What could they be from? I assume heavy railway equipment, but they are so rusted I have no clue. The amount of rust on them makes them look I n c r e d I b l y old. I found a 100 year old hammer left untouched in my backyard, and it had less rust than this. The pattern of the rust reminds me of wrought iron. Is this wrought or is it just because of how long it’s been rusting? Overall: What was this used for, how old is it, and what is it made of? Thanks!

grinder dust off a hot saw.

Think Mr. Pearson is right you got this ‘stalagmites’ when you cut / grind / flatten rail road tracks. A mixture of glowing iron/steel & corundum sparks/dust.  Like I got ‘baby stalagmites’ on the inside of my 9in angle grinder disk protection cap after cutting a big piece of bar.

Sometimes you can also find sprues from thermite welding of track.   I wonder how good an ore those stalagmites would be for a bloomery...

Wrought iron does NOT rust like that.

Oh wrought rusts just like that it just doesn't look like that.  

Frosty The Lucky.