“Life's just a merry-go-round. Come on up. You might get a brass ring.” - Mae West

User login

Welcome to iBrattleboro!

Welcome to iBrattleboro!
It's a local news source by and for the people of Brattleboro, Vermont, published continually. You can get involved in this experiment in citizen journalism by submitting meeting results, news, events, stories, reviews, how-to's, recipes, places to go, things to do, or anything else important to Brattleboro. Or, just drop by to see what others have contributed.

Find iBrattleboro on:

 Twitter YouTube

Authentically Local

Search the Archives

Ye Olde iBrattleboro Archive

Use the pulldown to choose desired number of results.

 

Search the first decade
of iBrattleboro archives
at Archive-It.org
Feb 20, 2003 to Feb 6, 2013

Mystery Rock


For years, I've been looking at this stone which I collected off the shoreline of the West River, up towards Williamsville.  I've not been able to figure out what it is.  Do any of our amateur (or professional) geologists know?

Although not obvious from this photo, the stone has a strong blue-green cast and is crystalline in nature.  The broken area at the top shows the crystal form somewhat, if you look closely.  There are a lot of stones of this type in the river around the area where I found this one, and I thought now would be as good a time as any to enlist the expertise of the community to finally identify it.

Mystery Rock

»

Comments | 10

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
 #

Soapstone

From your description and the pic I'm wondering if it's soapstone. How hard is it, i.e. how easy to scratch or carve into? If it is soapstone it may have been a larger piece of rock that was made into something, got dumped into the West River upstream when its useful life was done, and rounded itself out as it tumbled downstream. Sharp metal can pretty easily dig into soapstone. If this is the case your investigation might change from geological to archaeological in nature.

 
 #

Details, details

Thanks for the guess -- I don't think it's soapstone though as it's pretty hard although not as hard as quartz. It won't scratch glass as far as I can tell but will leave a permanent mark (not a scratch, per se) on a "copper" penny. It streaks white. In bright sunlight, the whole stone shows quite blue, esp the part where it's broken. Also, there's lots of it in the river below the bridge at Williamsville, so it appears to be from hereabouts or at least upriver. All examples of it that I've seen there are worn smooth.

I remember thinking maybe some form of tourmaline, in massive (as opposed to crystalline) form, but I looked it up and couldn't find an example that really looked like it. The color is closer to a fluorite but I've never seen that in the wild.

 
 #

The green at the top looks a

The green at the top looks a little like fluorite to me but I've never seen it in this form and know next to nothing about geology.

 
 #

romancing the stone

Maybe you could find someone who has a polishing set up and tumble a couple samples through a series of various carbide grits - course to polish ( a long process) which may better reveal and expose details and characteristics of this stone ( igneous, metamorphic ?) or just split one in half for a fresh look now apparently obscured by the wear of natural river wash / agitation.

At this point you could bring it down to Beadnics to be directed to a local knowledgeable source for identification. Even if it isn't a semi precious stone ( granite), if you like it, you like it, who knows it may even have particular healing properties of some sort for you or just feel soothing/isotonic to the touch rolling around in your palm when you need it.

 
 #

Quartz monzonite?

I've collected several pieces of this rock from the Rock and West Rivers (one nice specimen is in my fish tank) and always assumed it was some type of granite. Your post renewed my curiosity and I found an old description of granite quarries of the area and they described the local granite as quartz monzonite, which seems to fit the bill. If you do a little search of photos of quartz monzonite, you'll find examples that look very similar.

THE GRANITES OF VERMONT (look at pages 105-108)
http://pubs.usgs.gov/bul/0404/report.pdf

If you look on this page there's a photo of Maryland monzonite that looks similar to the rocks around here.
http://en.wikipedia.org/wiki/Guilford_Quartz_Monzonite

 
 #

Schist?

I didn't write in right away because the shape and whiteness argue against this.
VT streams are full of schist with garnets and the dark dots in your rock could maybe be garnets?
The problem is, schist is full of mica and shiny as a result. This rock has no sheen in the photo. I've also seen very few pieces of schist this shape - it tends to fracture along planes and be flattish.

Anyway, here's a link to a schist photo by the VT geology dept.:
http://www.anr.state.vt.us/dec/geo/images/KnoxMtnsPics/garnetDwaSchistMa...

 
 #

Robin sez:

Wholely schist, Batman!

 
 #

Trouble is, it's blue

I really appreciate all the help with my mystery rock. Here's the thing -- it really is blue. Or blueish, but not grey or white. And there's a lot of it in the West River where I found it. So that's why I'm having trouble with it. Schist that I've seen is grey with mica, usually. No mica in this stone, far as I can see, but there are specks of a very black mineral in it here and there. Also, it's pretty soft, with a hardness around 2-3 but harder than soapstone. Another thought we've had very recently is serpentine. But all the serpentine I've seen is dark green and waxy -- this stone is sort of pale, almost aqua blue.

One of my hobbies as a kid was rock collecting, but this one still has me stumped. I'm going to take another pic and see if I can capture the color better (which is subtle, I admit) and also a bit of detail. Someone has to know. ;)

 
 #

Full of schist

My first thought was that it looks like bluestone, so if it's blueish...

In Ireland and Britain there are a lot of calendar circles made with bluestone - Stonehenge has the remains of a ring of bluestone boulders around it, I think. According to lore and backed by my own observations, a bluestone boulder feels warmer to the touch than other types of stone that may be surrounding it.

 
 #

jadeite . It looks like a

jadeite .
It looks like a metamorphic rock. Combination of red garnet, quartzite, mica schist, maybe fools gold.

 

Local Ads

iBrattleboro Poll

At the amusement park, I want to ride the

Choices