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Help Identify this Dark Green Magnetic Glassy Stone

0 votes

Its dark green about softball size heavy somewhat glossy in places with many dimples and its magnetic - looks like there are pieces of iron embbed within the rock. I broke off a little shard and shined a light through it, so I know its also translucent.

asked Mar 8, 2018 by tonyp (120 points)

3 Answers

0 votes

There is no easy answer here. It could be slag imbedded in a concretion of sand and clay. Slag is waste metal, it would be magnetic. Sand and clay sediments form rock all the time. Differing conditions cause it to become rock over time, like sandstone, or the calcium in solution becomes calcite when the proper conditions are met. Another example is alluvial flow from a glacier picking up sand and other sediments and becoming puddingstone. Inside a puddingstone you will see other rocks around which the puddigstone was formed. As you can see, in the included picture there are stones which were picked up in an alluvial flow including jasper, quartz, a lake superior agate and more.

answered Mar 10, 2018 by Weasel (58,980 points)
0 votes
it seems to me that this stone does not bear any value, so I do not see the point in its exploitation?
answered Mar 13, 2018 by bernicestockstill (640 points)
0 votes
In general that appearance of glassy, bubbly material often indicates slag formed from post-mining operations. Without further testing that would be my first choice for identification.
answered Apr 29, 2018 by hershel (52,820 points)