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Identity HelpGreen Mineral on Stones... What is it?? (Epidote)

19th Dec 2015 18:54 GMTJonelle DeFelice

I posted this question on another forum and only got one opinion, so I am going to try asking all of YOU! :-)

Last year while walking around Belmont (MA, USA), I found a stone that was a bit odd. About softball size, it was heavy and round, with a patch of a light green mineral on it. Thankfully I had a bag with me, and I walked home with it. Last month, I walked around the same area and couldn’t find any more examples, even though I KNOW there was a few left there the year before.

Fast forward to this 12/17/15.

My father told me there were piles of acorns by our high school. I like to give them to the squirrels in our yard, so I parked my car by the school (or as we say in the Boston area, “paaahked my caaaaah”) and started walking around. I never found those acorns, but DID find some interesting rocks.

Our high school was built on what was once a brick company. In fact, there was at least one more brick company just east of it, in West Cambridge MA. There is a decent size pond in front of the school that is aptly named “Clay Pit Pond”, and there is supposed to be a steam shovel abandoned in the middle of it. Hundreds of local kids have had to jog around the pond for gym class, including myself. These days, I walk around the pond a few times of year to look for birds.

For the first time ever, I actually started staring at the dirt pathway I have trod on for years. And what did I find? More examples of rocks with the same green mineral I found last year! Good thing I had a bag with me again…

Can anyone tell me what this green mineral might be? It seems to be tough, seeing as these rocks have been in dirt/mud and driven/walked over for a long time with no apparent damage. Also, it seems to show up in/on various types of rocks. I even found one specimen that seems to be made completely of the stuff, THOUGH it is a paler green, so I may be wrong on that. Note also one that looks very “platy”.

(As usual, I had issues with the photos. Hopefully you all can get a good idea of what I have.)



More photos to come...

19th Dec 2015 18:57 GMTJonelle DeFelice




19th Dec 2015 19:00 GMTJonelle DeFelice


19th Dec 2015 19:02 GMTJonelle DeFelice

Also found were these examples, and I am wondering if they are the same type of mineral?



19th Dec 2015 19:09 GMTAlfredo Petrov Manager

They all look like Epidote (the green stuff). (The pink is Feldspar.) Here's what epidote looks like when it's better crystallized:

I find many of them in my area too. No commercial value for mineral collectors, because the epidote veins don't have good epidote crystals, but I save these rocks anyway - They make nice garden decorations. Sometimes lapidary artists polish this massive green material for carvings or cabochons - It makes an acceptable substitute for lower qualities of jade (as long as one doesn't cheat people by writing "Jade" on the label ;-) )

19th Dec 2015 19:13 GMTReiner Mielke Expert

Looks to me like epidote a very common mineral found on many different rocks. It is the result of the alteration of Ca-plagioclase to albite a process called epidotization.

19th Dec 2015 19:21 GMTJonelle DeFelice

Ah, ok. So nothing "fantastic".

The other forum now has 2 opinions, both serpentine. Now I am REALLY befuddled!!

Thing is, the Epidote here on the forum looks a lot different than what I have. I realize mine are not crystals, but the colors seem off.


19th Dec 2015 19:29 GMTReiner Mielke Expert

What other forum? Serpentine and epidote can look somewhat alike but serpentine can easily be scratched with a nail epidote cannot. Also serpentine feels smooth and soapy, epidote does not.

19th Dec 2015 19:30 GMTAlfredo Petrov Manager

Try scratching a pure smooth unweathered part with an iron needle. Serpentine is softer and will get scratched. Epidote is harder and the needle will just leave a metallic streak on the rock where some of the metal rubbed off.

19th Dec 2015 19:36 GMTJonelle DeFelice

Reiner Mielke Wrote:


> What other forum? Serpentine and epidote can look

> somewhat alike but serpentine can easily be

> scratched with a nail epidote cannot. Also

> serpentine feels smooth and soapy, epidote does

> not.

Is it PC for me to mention them? (FMF Mineral Forum) ;-)

I will have to try the scratch test. I am starting to think the mineral ON the stones is different than the solid green examples.

19th Dec 2015 19:55 GMTAlfredo Petrov Manager

The green-veined stones with pink feldspar in your 1st, 2nd, 4th and 7th photos are so definitely Epidote that I will eat my boots, in public, if they are not. The others.... well, do the scratch test for starters.

(PS: Just in case, for insurance, does anyone know where to buy boots made of chocolate?)

19th Dec 2015 21:28 GMTRalph Bottrill Manager

Fine grained epidote I reckon, compare with eg.

19th Dec 2015 21:33 GMTMaggie Wilson Expert

Alfredo Petrov Wrote:






> (PS: Just in case, for insurance, does anyone know

> where to buy boots made of chocolate?)

Google is your best friend, in this case, Alfredo.

19th Dec 2015 21:38 GMTAlfredo Petrov Manager

Thanks, Maggie! (I hope I won't need them ;-) )

20th Dec 2015 10:50 GMTErik Vercammen Expert

Alfredo, I back your view about the epidotes. And I'm willing to help you eat the (chocolate) boots in case we're wrong!

20th Dec 2015 14:37 GMTReiner Mielke Expert

I like chocolate, I'll help you even if you are right. Hell lets just get some chocolate boots and eat them.

20th Dec 2015 14:45 GMTAlfredo Petrov Manager

Erik and Reiner, You guys crack me up. It's fun knowing you :)-D

Edit: Maggie's chocolate boots photo seems to have disappeared. I bet you ate them already, Reiner, while we weren't looking :-X

PS - Jonelle, sorry for the distraction. As soon as you come back with the results of your hardness test, we can get back to discussing your green rocks ;-)

20th Dec 2015 15:10 GMTLarry Maltby Expert

Granite type rocks with green veins are commonly found in the glacial till and on beaches throughout Michigan. The massive type of epidote in these rocks has a characteristic shade of green that becomes recognizable with experience. I show below some cabs cut from a pebble found on a Lake Superior beach in Keweenaw Co, Michigan. The epidote is distributed through the “granite” with pink feldspar and clear quartz. The lapidary trade name for this material is Unakite.

20th Dec 2015 18:06 GMTPaul Brandes Manager

Chocolate boots!! now why didn't I think of those here in Texas????

The ladies here would go nuts for those if they didn't first try to put them on........ :-D

And I agree with epidote as being the green material in the first, second, and third sets of pics. The fourth set could something else that has been "epidotised" through metamorphism.

20th Dec 2015 20:07 GMTJonelle DeFelice

Hmmmmmmmmm... people really, REALLY like boots here! ;-)

OK, I did the hardness test... experienced collectors will probably laugh at me, as I used a safety pin to do it!

Here's what I found... Not much. The needle didn't effect the green minerals much at all. At most, I got a silvery streak from the pin tip that usually would come off with my finger.

Does this help?



20th Dec 2015 20:09 GMTJonelle DeFelice

... aaaaaaand the other, slightly different examples:


20th Dec 2015 20:20 GMTReiner Mielke Expert

Yes that is perfect, it shows that it cannot be serpentine so epidote it is.

20th Dec 2015 20:28 GMTJonelle DeFelice

Woohoo! Other forum proven WRONG!


Now I am wondering... could these examples have actually been "made" where I found them, or were they part of a MASSIVE load of stone/gravel when they turned the clay pit into a pond with a path around it? The fact I found my first example (not shown) about .5-.75 miles away, not near the pit, makes me think it is possibly actually from the location. When I dig deep in certain spots of our yard, I come across little blobs of clay. And our front lawn in summer could be put in a kiln with glaze and be used as a dinner plate!!

Does the formation of epidote ever have any relationship to clay deposits?

20th Dec 2015 20:32 GMTAlfredo Petrov Manager

Thanks, Jonelle, very clear pictures and good description of test results. (If only all the people who came here for identification help were as clear as you!) Use of safety pin is fine; I use them too. Result shows that the green mineral is harder than 5 on the Mohs hardness scale. So, yes, I think we can stay with "Epidote" as the ID. Damn... now I've no reason to eat the chocolate boots ;)

If you are into cutting and polishing stones, you could try making a cabochon out of the pink-green "unakite", like the very fine ones Larry displayed above. In my case, I'd just keep them as they are.

20th Dec 2015 20:43 GMTErik Vercammen Expert

Jonelle, Epidote has no relation with clay, so I suppose the stones are carried to that destination. They may have been quarried, or they come from a gravel pit where they were deposited either by streams or ice.

21st Dec 2015 02:20 GMTWayne Corwin


Chjange it to...

I won't eat my chocolate boots if I'm wrong! ;-)

It's epidote in most of the photos (tu)

31st Jul 2016 19:39 BSTJonelle DeFelice

What are the odds this is also most likely Epidote?

It is in a wall of the old quarry at Blueberry Mountain, Woburn MA. Not sure how else to link to photos I have uploaded to the "My Photos" section...

31st Jul 2016 19:42 BSTAlfredo Petrov Manager

The odds are indeed highly likely that that is epidote :)-D

10th Aug 2016 12:01 BSTUwe Kolitsch Manager

The odds are 100% :)-D

Caption edited.

10th Aug 2016 14:16 BSTMatt Courville

Hi Jonelle, I copied this for you from another post - hope it helps:)-D

To embed a picture from mindat, then you klick the "tourmaline(pink crystal)"-icon on the toolbar just abowe from where you write the new message/reply to messages. You will then get this line:

< pic id=XXXX width=600 float=left >

Then you open a new browser page and find the picture, then look at the site adress and copy the number in the picture page, and replace the XXXX. I have made the number in bold, and you can se the picture below as the result:

http: //

11th Aug 2016 20:51 BSTJonelle DeFelice


Like that???

12th Aug 2016 00:40 BSTMatt Courville

Looks good and works:)-D

12th Aug 2016 10:43 BSTMonika Kertowska

Hello everyone! This thread made my day ;) you guys are awesome! Jonelle,I love all your threads...

I came across a similar thing on the Dingle Peninsula in Ireland a few weeks ago... Could mine be epidote,too? It cannot be scratched with a needle and it seems to be spread in thin layers on a fine-grained greenish rock... No crystalline material,just solid stuff with cleavage similar to quartz. Attached find two photos.


12th Aug 2016 16:03 BSTJonelle DeFelice

Thanks Monika ;-)

I'm not used to seeing that stuff in anything so large! (tu) Is she right, folks?

12th Aug 2016 16:39 BSTMichael Wood

Hello Monika,

I would say without any doubt, that what you have is epidote. It is a very common mineral.

Did you find some nice quartz crystals on the Dingle Peninsula?

Hope your new mineral/shop/business is going well! ;-)

Cheers, Mike

12th Aug 2016 23:21 BSTMonika Kertowska


It's starting to roll... Sloooowly... ;) But I love what I'm doing! Thx.

Recently we had no luck but we'll be going again this year for sure.

Ok,I'm marking it as epidote and in it goes to my collection!
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