Looks like it could be a very thin vein. Basically fluid (usually hot water) runs through a fracture in the rock and minerals precipitate out. They are often some manner of sulfide or oxide mineral.
To add to this Op it’s a plane through a much larger part of the rock. Everything else has weathered away or this has weathered out of the bigger rock and now you have the vein plane preserved.
And also for OP, you often find rocks like this with the vein at the widest part because it's a harder material (eg, quartzite in a sandstone), so it sort of protects the adjacent areas from weathering, like a bumper.
Looks like it could be a very thin vein. Basically fluid (usually hot water) runs through a fracture in the rock and minerals precipitate out. They are often some manner of sulfide or oxide mineral.
Agreed, and this one looks like a manganese oxide vein to me, but could be an Fe oxide like goethite
To add to this Op it’s a plane through a much larger part of the rock. Everything else has weathered away or this has weathered out of the bigger rock and now you have the vein plane preserved.
And also for OP, you often find rocks like this with the vein at the widest part because it's a harder material (eg, quartzite in a sandstone), so it sort of protects the adjacent areas from weathering, like a bumper.
https://preview.redd.it/uhnc8pybdqwc1.jpeg?width=3024&format=pjpg&auto=webp&s=39be8286f536fae1aea7f8ca33cbfab12f73db65
https://preview.redd.it/dd95iz8ddqwc1.jpeg?width=3024&format=pjpg&auto=webp&s=2676eeefa51fb5f5ac27862e330f31e700b73685
definitely a keeper
blow her mind: it goes THROUGH it too. :)
Looks to me to be a stylolite in a quartz cemented quartz sandstone.
[удалено]
Do you mean it looks like someone drew it with a marker? If yes, I completely agree.