HOT ROCK

[Don In Virginia]

I sent a small sample of a rock like this to the U. of Minn. and was told that it is Hemitite or Magnitite. (Iron ore) Can anyone tell me why these rocks seem to give all metal detectors a fit. I found this one yesterday with the Ex.II and it read 00-31 in one direction and nulled in the other. ???????

 

[Rhoderman]

I don't know why they drive detectors nuts, but they seem to fake out the depth quite well too.
I had a hotrock that hit top right, just like a sweet silver quarter, and very repeatable. The depth gauge said it was down there about 8" or so. I started digging and pitched some rock aside a couple feet since it was in my way for digging. I dug and dug and kept sniffing the hole w/ my probe but couldn't get a scent of my target. Finally, after I had dug down about a foot, I rescanned the hole and my target had disappeared! I happened to swing over that stupid rock again and my sweet target had moved under it again, and it was still showing down about 8" repeatably!
I took the rock home and broke it open with a hammer, but there wasn't any silver coin inside it, much to my dismay... Mine had a tan crust on the outside, but stripes of black and grey inside in layers. I didn't have it analyzed, but I highly doubt it was silver ore!
Glad to see I'm not the only one getting all excited about a silly rock!
-Rhoderman

 

[Cody]

The early metal detector had a setting for minerals and metal and some were called metal mineral detectors. Our modern detector for coin and relic hunting only have the metal mode but does detect minerals. When we say a detector is ground balanced or rejects the minerals it is the minerals are detected and rejected. It is iron minerals that is the greatest problem. Some rocks have a concentration of minerals and will cause the threshold to go silent or increase so the minerals are designated as positive or negative and also as hot or cold. Rocks are also designated as hot and cold depending on the minerals and how they cause the detector to respond. A hot rock has a heavy concentration of minerals detected because it is different than the other minerals in the soil over which the detector has been balanced. Normal mineral change in a gradual way which a target responds very quickly. A hot or cold rock will give a quick response because of the abrupt quick change in the minerals in the soil and the rock. A hot rock will sound and can be pinpointed in the pinpoint mode. A cold rock will sound but cannot be pinpointed.

Hot and cold rocks are iron minerals in concentration that is different than the normal mineral over which the detector has been balanced. Since they contain iron they are detected. Some detector have a hot rock rejection setting but this can cost the user some good target also. I guess we all chase a hot or cold rock now and then.

 

[Don In Virginia]

Be careful, some hot rocks are meteorites and are VERY valuable. That

 

[DEEP SOUTH]

n/t

 

[Anonymous]

This seems to be a meteor that has been worn in glacial moraine the same way other glacial or stream worn rocks are formed; rounded.

 

[clockdryve]

Just by looking at it...........had me confused!!!! Looked like it even had a fusion crust. To bad