GeneralSunstone from Lincoln Tunnel
I recently acquired some beautiful sunstone material. It has been analyzed as sanidine, and was reportedly collected by a professor from Hamilton College who worked on the construction project of the Lincoln Tunnel.
Here are some pictures of the material...that's all the information I have available to me.
If anyone can offer some insight I'd greatly appreciate it.
If it was analysed as Sanidine, then it can't be "sunstone" as they are two different forms of feldspar. 
These may have been collected by a professor from Hamilton College, who also happened to work on the construction project of the Lincoln Tunnel, but it's highly unlikely the two incidences are related.
Lincoln tunnel is cut through Hudson Palisades diabase at it's western portal, Manhattan Formation schist at some point of it's bedding and termination on the island. No such minerals were ever recorded as encountered in these areas. To my knowledge, Oligoclase itself was encountered only at midtown Manhattan but not of the sunstone variety. The closest recorded sunstone locality to Lincoln Tunnel is about 40 miles north of it, in the Fordham Gneiss at Chappaqua, NY.
Most likely this professor had indeed collected them, but far more likely at some other locality than the Lincoln Tunnel construction site he had once worked at.
Pseudocubic Calcite w/ minor pyrite on diabase (Lincoln Tunnel construction site (1934-37), Weehawken, Bergen Co., NJ)
ex Walter E. Kuenster collection #812 7.2 x 4.2 cm 
Thanks Mark--I think that I learn something with each of your insightful posts! 
Mark, that's a great calcite specimen and photo! Can you put it in the database (don't see it there)?
I'm a fanatical NYC & vicinity collector, and always looking to pump up the specimen photos from there in Mindat. Thanks Mark and Paul for the information.
If anybody has any suggestions as to where this material may be from, I would greatly appreciate any help.
Thanks 
Pu Tzu,
I saw your post and have some information that may be helpful to you. Please take a look at this mineral I posted today:
https://www.mindat.org/photo-903122.html
This was from Joe Cilen's collection, and collected in the 3rd Lincoln Tunnel (the newest tunnel) which was under construction between 1954 and 1957. Joe's label. His label states albite, but this clearly looks more like microcline. As I mention on the page, this is most certainly from the Manhattan side of the tunnel with and not the diabase from the Weehawken (NJ) side of the tunnel. The back of it contains extensive muscovite mica with a silvery color.
This feldspar material does have the semblance of sunstone, as its the right color and texture, but its missing the iridescent sheen. Perhaps other material from the same find does have that sunstone-type of the iridescent effect.
Anyways, I hope to be in Springfield this weekend, and hope to see you there where we can chat about this in person. Hershel
That looks like Perthite to me, both albite & microcline.
See you in Springfield. Wayne,
Thanks for the suggestion. There is definitely the veining indicating the possibility of more than one feldspar type, so perthite is a logical assumption. I still believe its from the Manhattan side of the tunnel as that assemblage is much more logical than the New Jersey side which is diabase. See you in Springfield hopefully! I'll be sporting a minerals.net cap so I should be easy to find. As far as visually distinct feldspars, only peristerite was noted as found at 16th Street and Fort Washington Avenue in northern Manhattan, and more recently, "Orthoclase, variety adularia, has been collected during recent work on Water Tunnel No. 3 under Manhattan and has been confirmed by analysis at the NYSM". (via John Betts, "The Minerals of New York City" Rocks & Minerals, Volume 84, No . 3 pages 204-252). There has never been any record of sunstone recovered in the N.Y.C area to my knowledge.
Fordham Gneiss is exposed only in the Bronx, but portions do extend into the subsurface of Manhattan, the Manhattan group schists themselves are frequently intruded with crosscutting granitic pegmatites, so the potential sources of encountering variable felspar group minerals is present, but I am troubled that in this area's long history, no record was ever made of such a discovery (again, to my knowledge).
These cut stones in particular look like rather fine examples, which only adds to my doubt of any assumptions for a N.Y.C. origin. Of course, it would be a shame if they actually were from an isolated occurrence of the tunnel workings, but the discovery kept hidden and as a result, now little more than a somewhat dubious claim, with no additional or previous observations in the region to lend it credence.
I'd be curious to hear what John Betts thought of these.
MRH I spoke with John about these first...and he was fairly certain that there were never Sunstones found in Manhattan.
An update since I've been doing the research. I will follow up with more details in a day or two.
The stones were analyzed as Sanidine.
I have also tracked down 4 layers of the source...getting to the bottom of things as much as I can.
And I have confirmed as much as I can that they were collected by Mike Dubrowski who's father was a civil engineer who worked on the project.
As I said, more info will be posted as I find it...back to work
Oh yeah, this material will be at the Denver Show next month if you want to see it in person. 
To add some additional context to the Cilen specimen noted above, I own his extensive card file, and specimen #8341 was purchased from Dick Hauck in December, 1977, ex-Calcina. 
When I got out of college back in 1983, I got a job with a Geotechnical Engineering firm and got sent to a site in Jersey City, NJ to take sediment cores on the Hudson River shoreline in advance of construction of one of those office towers that now line the New Jersey side of river. Once we got down to bedrock, several hundred feet through the muck and mud, we brought up a schist like material with vivid blue laths that I assumed were kyanite. So the New Jersey side of the Hudson may have diabase cliff walls, but is Manhattan schist down below. If these specimens are truly from the Lincoln Tunnel construction, the final unknown may be which state they are from. Tony,
You have Joe Cilen's card file?! "Extensive" is putting it mildly!
One of my Snake Hill Apophyllite from his collection is specimen #20,477. I understand his final count was over 23,000. I can only imagine . . .
MRH I had the chance to look at these at the Denver Mineral & Fossil Show a few days ago. There is not much I can add, but I did look at the XRD printout (from Attard Minerals) and photographed it, and Pu Tzu gave me permission to upload it here. The stones are quite beautiful. All the original rough has been sliced up and polished, apparently. There is a second analysis of some black grains in the material which were analyzed as magnetite.
