sampson
starting to spend too much on rocks
Member since April 2011
Posts: 222
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Post by sampson on Nov 6, 2011 19:04:37 GMT -5
I recently moved into a great new place which has a ton of neat rocks around. I haven't spent much time around here before moving here so many of the rocks are pretty new to me and although i have found quite a few cool ones so far i have no idea what some of them are. These are found in less than a 10 minute walk from my house at the base of the cliffs in the Bonaparte Valley, B.C. Canada. They are fairly hard and do not scratch with a knife and i think they will polish nice. They have a bit of a waxy feel almost like jade. Slightly translucent as can be seen in some of the chippy areas in the pics. Non magnetic as far as i can tell. I haven't done any SG tests yet. These occur in a bit of a seam and lenses near the base of some 200 foot high cliffs and seem to be metamorphics with softer, more grainy material transitioning into more solid and pure material in the middle of the seams and lenses. Cleavage seems fairly random and chips are very sharp but many of them are so full of fractures i haven't been able no knap any pieces. I hope that provides enough background info to get some educated guesses but if anyone has any specific questions or more info i should provide please let me know. Any thoughts, ideas, or guesses as to what they may be are appreciated. First is a large piece that is very chippy but has a great translucence and color. Next two pieces show some different colors from the middle of the lenses with the more standard blue/green/grey outside i seem to find a lot of, more opaque and less chippy. This piece has some nice dark vein inclusions and i think it would make some nice patterns once i get some time to get some slices of it. This last one has the same black veins but is very solid with no real fractures through it and shows a neat break line at the one edge. I should have some time in the next few days to get my saw set back up and take a couple slices into these and i will be sure to post the pics and results when i do. If anyone has any guesses or ideas what they may be i would sure like to know. Sampson
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
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Post by Sabre52 on Nov 7, 2011 20:51:01 GMT -5
All the rocks except those shown in the third picture appear to be quartzite or massive quartz though the last one, like number three, may be green jasper or chert. All except the first example which appears to be pretty fractured, should polish quite well.....Mel
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mjflinty
spending too much on rocks
Member since September 2011
Posts: 356
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Post by mjflinty on Nov 8, 2011 8:16:32 GMT -5
Looks like Novaculite to me but, you are long ways a way from Arkansas. Hummm, perhaps it's a chert... the one photo shows the right fracture. Have you checked on your local geology maps to see what kind of formation you are at?
Michael
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sampson
starting to spend too much on rocks
Member since April 2011
Posts: 222
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Post by sampson on Nov 8, 2011 11:46:31 GMT -5
Thanks for the ideas guys. I am not sure about being quartzite, since most quartzite i am familiar with is more grainy under magnification and broken or weathered pieces end up with a sort of "sugary" looking fracture. Unless this was a layer of more silty or muddy stone with much smaller particles than sand, or completely metamorphed to eliminate the appearence of the individual grains. My original guess was a form of chert although the first piece in my pics has such a wierd looking chippy fractured surface it kinda throws me off. To me the first piece almost looks like dried out, crazed, common opal but with the straight edged break lines it throws me off too. I was able to look at it under good magnification last night, (about 20X) and i can't make out any individual grains, but it did seem to have a bit of a wierd reflection look in some of the more transparent areas. I wish i could post magnified pics. I have tried searching for more info on the geology in this area although everytime i search i keep finding more information on Napolean Bonaparte then the Bonaparte Valley. My Web-Fu is not strong when it comes to searching but i will keep at it as i have time. Any other thoughts, ideas, or tests i could do to try to id these are appreciated. I should have time to cut some up later today so that may provide some more insight. Sampson
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sampson
starting to spend too much on rocks
Member since April 2011
Posts: 222
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Post by sampson on Nov 9, 2011 16:51:14 GMT -5
I was able to cut off a 1 inch chunk today off of the first piece i posted in this thread. I think i can safely rule out common opal since it was so damned hard it cut tougher than most agates i have cut. I was impressed that when i cut it it seems to be pretty solid inside and i should be able to get some nice chunks to tumble and may end up cabbing a few pieces. I'm still not sure what i would call this stuff although i am pretty sure it is quart based and chock full of veins of different materials which also look like quartzy stuff. If anybody has any ideas what to call this i would appreciate any info. I took two different sets of pics with different light strengths to give a bit of a view further into it. The darker one looks more like it does in my hand, fairly translucent with great orange colors. The lighter pic was taken under 3 big photo lights to give a different look into it. So basically this, Looks like this on the inside after i cut the chunk out. It is kinda wierd in one other way in that it seemed to soak in the water i soaked it in for a while. I'm not sure what this would mean other than it is slightly porous even though it looks very solid even under magnification? I did cut one of the smaller grey pieces as well but it just looked pretty plain with nothing special about it. I may try slicing a slab of it and see if it knaps well since it seems like it would. Sampson
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Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
Posts: 891
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Post by Minnesota Daniel on Nov 10, 2011 0:14:39 GMT -5
Jade
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sampson
starting to spend too much on rocks
Member since April 2011
Posts: 222
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Post by sampson on Nov 16, 2011 21:59:35 GMT -5
Thanks for the guess Daniel but it's definitely not jade. I did some SG tests on two pieces today and one came out at 2.05 sg and the other one came out at just over 2.00 sg. The 2.05 piece was the first piece in my pics and the same one in my last post that i had cut. The 2.00 one i haven't taken a pic of yet but it prety much looks like the last pic in my first post in this thread.
With such a light sg it confuses me even more and i guess it throws quartzite, jasper, or chert out of contention. It doesn't scratch with a knife but i tried a piece of the amethyst i found recently and it scrathes it easily so i guess that makes the hardness around 6 - 6.5
There is a ton of this stuff in varrying colors and purity/solidness in the cliffs right out back of my place and as soon as i have an empty barrel i am going to try tumbling a load to see how it polishes and how it looks when it is smooth and shiny. I think it will look nice with the subdued almost soft looking colors in it as long as it holds together well.
If anybody else has any guesses now that i know the SG and have a better idea of the actual hardness i would sure appreciate knowing more about what this stuff is.
Sampson
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Minnesota Daniel
freely admits to licking rocks
A COUPLE LAKERS
Member since August 2011
Posts: 891
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Post by Minnesota Daniel on Nov 18, 2011 2:46:13 GMT -5
Sampson,
Maybe you have Bowenite, with opal. I believe that combination is possible. I think you are going to need to contact the Ministry of Energy and Mines for the Province to get an answer.
Daniel
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on Nov 18, 2011 14:56:47 GMT -5
Almost has some feldspar -like qualities to it...
definately not jade, jade never has that clean fracture evident by the chipping on the surface...
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agatemaggot
Cave Dweller
Member since August 2006
Posts: 2,195
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Post by agatemaggot on Nov 21, 2011 22:38:00 GMT -5
The second picture down looks like it has reflective flakes in it similar to Larvacite, may not have spelled that one right but I have seen counter tops made from it. The examples I have seen have been Gin clear with large reflective flakes. The slabs, 4 ft. x 12 ft. have a Charcoal color to them.
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