negativenull@piefed.world to Cool Rocks@lemmy.todayEnglish · edit-212 days agoCool rock I found in a parking lotlemmy.todayimagemessage-square5linkfedilinkarrow-up162arrow-down11file-text
arrow-up161arrow-down1imageCool rock I found in a parking lotlemmy.todaynegativenull@piefed.world to Cool Rocks@lemmy.todayEnglish · edit-212 days agomessage-square5linkfedilinkfile-text
minus-square1984@lemmy.todaylinkfedilinkEnglisharrow-up3arrow-down1·12 days agoI asked chat gpt because I was curious… The rock appears to be iron-stained sedimentary rock, most likely: Sandstone or siltstone Reasons: Brown/yellow coloration typical of iron oxide (limonite/goethite) staining Visible layering and flaking, suggesting sedimentary bedding Fine-grained surface (no large visible crystals) Breaks along planes rather than showing crystalline fracture The reddish area The darker red patch may be: A small iron-rich concretion Or possibly a fragment of jasper (iron-rich microcrystalline quartz) embedded in the host rock Less likely options Not granite (no visible interlocking crystals) Not basalt (wrong color and texture) Not metamorphic schist (no clear foliation or mica sheen) If found in Scandinavia, this type of iron-stained sandstone/siltstone is common in sedimentary formations and glacial transport deposits. For more certainty: Check if it scratches glass (quartz-rich sandstone will) Drop vinegar on it (if it fizzes, it contains calcite → limestone component) Note where it was found (coastal, inland, quarry, etc.) Most probable identification: Iron-rich sandstone or siltstone.
minus-squarenegativenull@piefed.worldOPlinkfedilinkEnglisharrow-up2·12 days agoThat’s interesting. I’ll have to do some tests. Thank you!
I asked chat gpt because I was curious…
The rock appears to be iron-stained sedimentary rock, most likely:
Sandstone or siltstone
Reasons:
Brown/yellow coloration typical of iron oxide (limonite/goethite) staining
Visible layering and flaking, suggesting sedimentary bedding
Fine-grained surface (no large visible crystals)
Breaks along planes rather than showing crystalline fracture
The reddish area
The darker red patch may be:
A small iron-rich concretion
Or possibly a fragment of jasper (iron-rich microcrystalline quartz) embedded in the host rock
Less likely options
Not granite (no visible interlocking crystals)
Not basalt (wrong color and texture)
Not metamorphic schist (no clear foliation or mica sheen)
If found in Scandinavia, this type of iron-stained sandstone/siltstone is common in sedimentary formations and glacial transport deposits.
For more certainty:
Check if it scratches glass (quartz-rich sandstone will)
Drop vinegar on it (if it fizzes, it contains calcite → limestone component)
Note where it was found (coastal, inland, quarry, etc.)
Most probable identification: Iron-rich sandstone or siltstone.
That’s interesting. I’ll have to do some tests. Thank you!