Category Archives: Minerals

Tourmalines

An article I wrote for the April, 2014 WCGMC News  (www.wcgmc.org)

ALL TOURMALINES ARE NOT CREATED EQUAL

When we venture to Ace of Diamonds to dig clear quartz crystals we are seeking a very simple mineral, silicon dioxide (SiO2).  Just simple SiO4 tetrahedrons joined together with each large oxygen atom shared by two small silica atoms in a six-sided prism, ideally terminated by 6-sided pyramids.  And when we seek that elusive fluorite at the annual Walworth Quarry dig, it is just calcium and fluorine combined into a cubic lattice motif with Ca atoms centrally located and F at the corners.  This time each of the 8 fluorine corner cube atoms are shared by four unit cells with the formula CaF2.  In both minerals inclusions generate color variations which get neat names (like amethyst or citrine).  Of course, quartz can twin or show spectre form, but there is no elemental substitutions of note into the lattice of either mineral, and there are no solid solutions to confuse collectors:  just simple SiO2 or CaF2, just quartz and fluorite.

It is not as simple with tourmaline.  When we travel north to St. Lawrence County to collect dravite at Powers Farm, or fluor-uvite at Bush Farm or Selleck Road we are focusing our attention on one of the most complex mineral structures known.  The mineral lattice of tourmaline actually has five structural sites where elements can be swapped and traded, six if you count the rare substitutions of aluminum or boron into the Si site.  These substitutions can be complete or partial, and often occur in zonal patterns such that the center of the crystals actually may qualify as distinct minerals from their outside layers.

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Lewis Mine, Willsboro, NY

Article I published in March, 2014 WCGMC News

Mineral collectors appreciate the golden amber grossular garnet and green diopside offset by the brilliant white of the matrix wollastonite.  Students of SUNY-Plattsburg learn about contact metamorphism from Dr. Mary Roden-Tice during field trips to the locale.  Economic geologists appreciate the mine as one of only two active wollastonite producing mines in the United States, both of which are in New York State (the Valentine Mine near Harrisville is the second).  But to many New Yorkers, the Lewis Mine of Willsboro Township in Essex County, New York went about its annual production of about 60,000 tons of wollastonite (~10% of the world’s production) in quiet anonymity.

lewis mine 1

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Selleck Road, West Pierrepont, NY

Occupying an east-west ridge just south and parallel to Selleck Road in West Pierrepont this location has been collected for decades.   The main part of the ridge is on state land and accessible without much walking, thereby adding to the popularity of the site.  Tremolite is everywhere, tourmaline (v. uvite) is much more localized along the ridge.  Both the light green tremolite and the uvite is typically etched and non-gemmy, however isolated pockets of very gemmy material has been found.

Selleck road

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Benson Mines, Star Lake, NY

Have you driven Route 3 in southern St. Lawrence County?   Did you know that as you pass just east of the small hamlet of Star Lake you are just hundreds of feet south of what was once the largest open pit iron mine in the world?  That’s right, in 1958, during the height of its life, the Benson Mines open pit iron mine held that lofty title.  The pit was 4 kilometers long, 250 meters across and 400-600’ deep.  Today the pit is host to a whole lot of brilliant blue water and the surrounding Appalachian Park region is forest covered and virtually pristine wilderness.

The high concentration of iron in the rocks of the region was first recognized in 1810 when engineers surveying for a military road found their compasses wandering.  But until the timber industry built a railroad to the region the iron ore could not be exploited.  Even with rail, the area was still remote and from 1890 to 1940 mining was sporadic and limited.  In 1941, Jones and Laughlin Steel Company leased the properties and constructed plant facilities. Continue reading

Minerals on Stamps

On November 14, 2013 I presented a program simply entitled “Minerals on Stamps” to the Rochester Philatelic Association.  As a retired geologist, collecting minerals and other geology related topical stamps is a natural merger of my collecting interests.

Did you know that the checklist of gems and minerals on stamps maintained by the Gems and Minerals Study Unit of the American Topical Association has over 3000 entries?  Or that all 8 of the US mineral stamps depict specimens that reside in the Smithsonian?  The FDC with the four 10 cent stamps issued in 1974 is depicted shown below.  The mineral specimen in the bottom stamp is affectionately referred to as “The Postage Stamp Tourmaline.” It is from the pegmatite mines outside San Diego, CA.

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Rose Road, Pitcairn, NY

An article I wrote for the WCGMC News in December, 2013

One of the more popular mineral locations for upstate New York rockhounds this year was Rose Road off Route 3 in Pitcairn, a daily fee site owned by Mr. Richard LaPlatney who lives at the property.   Although the silicate skarn mineralization flanking the Grenville age white marble hill has been visited by mineral collectors dating back to 1880’s the location seems to have been rejuvenated after Walter highlighted the mineralogy and collecting history in his 2007 book “Field Collecting Minerals in the Empire State”.

The major “digging” there this year was focused on the first site encountered after passing LaPlatney’s home just off of Rose Road.  At first glance the exposed rock seems to be dominated by lavender diopside, calcite, albite and red brown phlogopite..  A Scanning Electron Microscopy/Energy Dispersive Analysis (SEM/EDA) of the lavender diopside indicated elevated Ti, likely substituting into the Mg spot in the lattice to generate the lavender color (S. Chamberlain, pers. comm.).  There is also less Fe in the purple diopside than in the green version found just a few hundred feet farther up the road.

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A New Tremolite Location in Canton, NY

A friendly local mineral collector shared a new site with Dick and Jeanne Phillips and Fred Haynes during the St. Lawrence County show in Madrid, NY in August.  Apparently, Wildwood Road east of Colton, NY was not draining well and the county decided to level the ground on both sides of the road to improve runoff.  In doing so they exposed bright white marble outcrops that were cut by zones of orange calcite, light green serpentinite and green tremolite.  And right on the road !

This pretty garden rock consisting of dark green shiny tremolite and orange calcite set into a finer grained lighter green serpentine was just sitting on the side of the road waiting for us.  Dick just backed his "truck" right up to the 50 pound puppy.

This pretty garden rock consisting of dark green shiny tremolite and orange calcite set into a finer grained lighter green serpentine was just sitting on the side of the road waiting for us. Dick just backed his “truck” right up to the 50 pound puppy.

Two St. Lawrence County Sites

On Tuesday August 20th, nine RAS members met outside St. Lawrence Zinc’s famous #4 mine in Balmat, NY.  The party included Gary Mosbruger (who was helpful in setting up the visit), his sons Alan and Bryan, John Klahn with his sons Anthony and Ryan, Jerry Curcio, Paul Dudley and me.  Once at the mine location, we were met by Bill deLorraine, Senior Geologist for the mine and also the President of the St. Lawrence County Rock and Mineral Club.

Bill led us upstairs for a safety briefing and to view some of the large fine mineral and ore specimens that have been recovered from the lower levels of the mine.  Then he turned us loose on the ore piles and drill core pieces that were conveniently stacked adjacent to the main shaft.  We were able to collect what we could carry.  Much of the ore was massive to near massive red-brown sphalerite, often speckled with small disseminated pyrite cubes.  Elsewhere the sphalerite swirls through the host marble as jelly in a jelly roll.   Unfortunately the nature of the occurrence does not lend itself to crystalline ZnS, but cleavage faces sure reflect sunlight making for pretty rock specimens.  Sphalerite is soft (hardness of 3.5), so cabochons and other polished surfaces do not make good durable jewelry pieces, but they can be most decorative.

Does anyone want to guess how many pieces of core Paul managed to get into his blue backpack ?

Does anyone want to guess how many pieces of core Paul managed to get into his blue backpack ?

I have not done much with the drill core I packed out, but I did make sure to recover a little of all available rock types.  In addition to the red-brown sphalerite swirling through the white marble, pure white marble, light-green serpentinite (often spotted in marble), and orange calcite were all represented in the core..  In addition some of the metasediments (now schists and gneisses) are pretty in their own right when captured in a 1 3/8th inch diameter core.

My selection of drill core

My selection of drill core

We left Balmat a little after noon and headed over to Rose Road off Route 3 in Pitcairn.  Everyone was intent on finding that elusive big sky blue apatite together with the pretty lavender diopside at the northern most digging on the property.  We did find some, but recovery was not easy and most were small.

Paul and I puzzled over this bluish mineral  intergrown with the diopside, red-brown phlogopite, and calcite.

Paul and I puzzled over this bluish mineral intergrown with the diopside, red-brown phlogopite, and calcite.

Paul speculated that this mineral might be scapolite at the outcrop, but we were less certain once back in Rochester as scapolite was not in the previously published mineral list for the property.  I sent a picture to Steve Chamberlain given the locality was included in his recent book.  Steve responded promptly telling us that significant scapolite had been recovered at the site this season and that our samples were definitely scapolite (~ 50% each end member Na-rich marialite and Ca-rich meionite by SEM/EDA).  He sent this picture of one of his specimens.

Scapolite (var. meionite) from Rose Road.  Specimen and photo by Steve Chamberlain.

Scapolite (var. meionite) from Rose Road. Specimen and photo by Steve Chamberlain.

An  SEM/EDA analysis of the lavender diopside indicated elevated Ti, likely substituting into the Mg spot in the lattice and likely affecting the lavender color (S. Chamberlain, pers. comm.).  There is also less Fe in the purple diopside than in the green version just a few hundred feet up the road.

We continued to that second site and collected green diopside with albite and occasional chocolate brown titanite..  I particularly like the samples with bright white crystalline albite intergrown with the diopside.  And naturally, everyone took their fill of blue calcite from the boulders that line the road to the radio tower.

Chocolate brown titanite crystal, two green diopside crystals, floating in diopside psuedomorph after wollastonite, a very interesting mineralogic piece.

Chocolate brown titanite crystal, two green diopside crystals, floating in diopside psuedomorph after wollastonite, a very interesting mineralogic piece.

Before leaving, Paul and I explored a bit behind the radio tower atop the marble hill and believe we discovered a previously unknown mineralized outcrop.  Everything was covered by moss and lichen, but I took a couple pieces home and applied bleach.  The result showed orange calcite, green diopside and white albite.  Strongly etched on this surface sample, but perhaps a new site to dig come spring ?

Diopside, orange calcite and and white albite from a new location behind the radio tower.

Diopside, orange calcite and and white albite from a new location behind the radio tower.

Before leaving, Paul and I explored a bit behind the radio tower atop the marble hill and believe we discovered a previously unknown mineralized outcrop.  Everything was covered by moss and lichen, but I took a couple pieces home and applied bleach.  The result showed orange calcite, green diopside and white albite.  Strongly etched on this surface sample, but perhaps a new site to dig come spring ?

 

 

Owen Prospect, Pierrepont, NY

Unlike many St. Lawrence County locations, the Owen Prospect off Irish Settlement Road in Pierrepont is a newly discovered site.   But like many others, the mineralization here is scattered and geologically diverse.   Exposed outcrops of marble are cut by silicate bearing assemblages.  As the silicates are a bit “softer” it appears that the best collecting process may involve finding some loose weathered out mineralization in the dirt and digging down to bedrock.   The few locations that have yielded nice specimens to date do not appear to have been found from outcrop.

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Benson Mines, Star Lake, NY

September 14, 2013:  I met up with the St. Lawrence Mineral Club and the SUNY-Plattsburgh Geology Club for an interesting visit to Benson Mines in Star Lake, NY.   Approximately 12 members of the St. Lawrence Club and 15 undergraduates from Plattsburgh were guided through the property by the current caretaker of the property, George Peerson.

Benson Mines was an open pit iron mine that exploited a magnetite-martite rich unit in the high-grade metamorphic terrain of the Appalachian Lowlands. The pit is not a beautiful tree-lined lake just north of the town of Star Lake on Route 3.

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New York Mineral Collecting

New York is rich in mineral collecting sites.  Many have been known for hundreds of years, but others are being found every year.

The purpose of this site is to capture personal knowledge of sites I have visited, and others that I would like to visit.  This input includes maps, field pictures, mineral photos, and literature references.   It is not meant to be complete in any category, and I intend to continually add to the site as I explore New York geology and minerals.