Please help me identify this.

[carida83]

Hi! My name's Carla and I'm new! A question I have is:
I found this in my garden does anyone know what it is?
Quite heavy, and the black is very dark and not magnetic.
Update:
We used a diamond detector, it beeped and reached the red light, so probably it's a precious stone, but not sure witch one.

TIA

 

[Rock Jock]

Hi Carla! Welcome to our metal detecting forum. Questions! What is the general location where your garden is located (State, physiographic province, nearby large urban area.), so as to characterize the geology a tad better? How soft is the black mineral and have you tried to do a streak test on porcelain yet (the rough unglazed bottom of a porcelain dish will suffice)? If it crumbles easily and has a black streak, that is useful info. I trust that I am seeing several reddish crystals in the otherwise black rock matrix? You might try to mark a piece of notebook paper with the black mineral to see if it leaves a mark on the paper without tearing it, as you would with an artist's charcoal. Just based on imagery appearance, I'm inclined to identify it as a metamorphic rock. That suggests that you may be near some mountains, or at least a metamorphic exposure of some sort. Did you test the reddish crystals or the black matrix or both with your gem tester?

 

[carida83]

Hello Rock Jock, thank you for answering my question and for your help.
I am based in Norfolk in the UK.
The whole stone is rock hard and won't crumble or mark the paper
Nope no mountains near us, it is a very flat county lol.
I only tested the white part lol.
But will do it soon and let you know.
Again thank you so much for your help.
Kind regards
Carla

 

[carida83]

Hi Carla! Welcome to our metal detecting forum. Questions! What is the general location where your garden is located (State, physiographic province, nearby large urban area.), so as to characterize the geology a tad better? How soft is the black mineral and have you tried to do a streak test on porcelain yet (the rough unglazed bottom of a porcelain dish will suffice)? If it crumbles easily and has a black streak, that is useful info. I trust that I am seeing several reddish crystals in the otherwise black rock matrix? You might try to mark a piece of notebook paper with the black mineral to see if it leaves a mark on the paper without tearing it, as you would with an artist's charcoal. Just based on imagery appearance, I'm inclined to identify it as a metamorphic rock. That suggests that you may be near some mountains, or at least a metamorphic exposure of some sort. Did you test the reddish crystals or the black matrix or both with your gem tester?

Okie so both red and black are on the number 8.

 

[stetam]

Kingtotsalot will know

 

[Rock Jock]

Okie so both red and black are on the number 8.

I tried to view Norfolk County at the British Geological Survey free online geology data mapping portal, but was unable to bring it up on my Kindle for viewing. I don't have my laptop with me presently. I suggest you take a crack at it if you have access to a good computer. You would also have an easier time trying to talk to a BGS human being for help negotiating the nuances of their online mapping system. This would likely provide info on your local surficial and bedrock geology.

 

[DCCraftsman]

Could it be a chunck of basalt with quartz and garnet?

 

[Sorthious]

Could it be a chunck of basalt with quartz and garnet?

I find rocks with Garnet in it all the time. It's always varying degrees of red to purple. I found a nice one that wasn't encased by other rocks and crystals.