Gemstone Occurrences in Massachusetts

This is rhodonite of the type found in the Betts Mine it is also the state gem of Massachusetts
Photo by Phillipe Giabbanelli

Massachusetts is another state that is sparsely supplied with gemstones although there are some exceptions one of which is the Betts Mine in West Cummington that produced some very fine rhodonite for years.  The rhodonite accompanied by rhodochrosite is respectively manganese silicate and carbonate both are cut as gems.  Rhodonite is also the state gem of Massachusetts. 

Rhodonite was first discovered as float from the glacier during the 19^th century where the American Gem Company part of Tiffany & Co., became aware of the float.  They used the rhodonite for making knife and umbrella handles as well as dinnerware.  There is a place setting on display in the American Museum of Natural History in New York City made from rhodonite from Massachusetts.  The deposit that is at the contact between the Hawley and Savoy schists was developed by Anson Betts who mined the rhodonite for use as flux on welding rods and later mined it as a gemstone.  The mine was bulldozed shut after the death of Anson Betts and is now closed to collecting.  Rhodonite is still available from the site in the form of mine tailings where it is still collected.

Down the road from the rhodonite deposit to the east is the small village of Lithia in the town of Goshen where the mineral called spodumene was mined in the late 1800s.  This is an area of LCT pegmatites where the first colored tourmaline was discovered in a quarry in the town of Chesterfield in the early 1800s.  Goshen is the Dana type locality for the variety of beryl termed “Goshenite.” a colorless variety of beryl.  The same pegmatites also produce blue tourmaline, petalite and pollucite a cesium aluminum silicate mineral. Beryl has also been found in a pegmatite at Royalston in Worcester  County.

This is margarite a rare form of mica on emery from the mines at Chester, MA.  Emery is the black mineral that the margarite is hosted upon.  Margarite is a brittle form of aluminum rich mica associated with emery deposits.
Photo by Rob Lavinsky

The Chester Abrasives Co. in Chester used to produce emery from the mines west of Chester in about the area where the power lines cross US RT. 20 in a series of mines running north to south for a total of five mines.  In the historical society of Chester there are four apothecary jars containing several pounds of ruby and sapphire crystals that were actually mined in the Cowee Valley corundum mines in Franklin NC operated by the Chester Abrasive Co. in the late 1900s.  Although not mined in Chester they are at least worth a good look.  There is an exposure of gem grade serpentine on the Middlefield Rd. on the right just as you are climbing out of the Westfield River Valley.

The Connecticut Valley offers a completely different suite of gemstones.  The first place to look is in the gravels of the lower Deerfield River because it contains agates that have washed from the nearby trap ridges.  The trap ridges themselves offer good deposits of amethyst and zeolites.  Lanes Quarry in Westfield is the Dana Locality for datolite, however Lanes Quarry is closed to collectors as it is an active quarry.

Datolite from Lanes Quarry in Westfield
Photo by Rob Lavinsky

Garnets are found throughout the state wherever there are crystalline rocks although many of them are rotated making them useless as gemstones.  Most of them are almandine garnets although in the Betts Mine that contains the manganese minerals rhodonite and rhodochrosite there are a rare variety of orange colored garnets called spessartine that are gemmy and suitable for faceting.  Many of these garnets tend to be small, but there are some exceptions weighing several carets.

Spessartine garnets of the type found at the Betts Mine in Plainfield MA where they occur with quartz.
Photo by Rob Lavinsky

A good source about rocks and gems in the state can be found at the many gem and mineral stores dotting the landscape.  Most of these stores stock guidebooks that give specific localities for collection, and many of them are up-to-date,

Gemstone Occurrences in Vermont

Grossular Garnet found at Eden Mills Vermont is the State Gemstone.
Photo by Rob Lavinsky

Vermont is a beautiful state, but when Mother Nature was handing out gemstones she passed over Vermont handing out very few of these stones. Finding any quality gemstones in the state is more then a little like looking for a needle in a haystack.

The Vermont Gemstone is the grossular garnet that is found at Eden Mills from the Belvidere Mine.  This mine has produced some of the best specimens of this kind of garnet that have ever been found. 

There are no extensive pegmatite deposits in Vermont although beryl crystals are found with albite in Fairfax.  Beryl crystals are found penetrating the albite at this locality.  Lake Willoughby in Orleans County is one of the few places in Vermont that does have gem bearing pegmatites.

Blue Quartz is contained in the Precambrian gneiss found in road cuts along Rt. 9 east of Bennington as you are climbing out of the valley. Smoky quartz crystals are found in the vicinity of Lowell.

Corundum has been found on Granite Hill in Cuttingsville and Shrewsbury in Rutland County Vermont according to several authorities.

Jasper is found along the East Coast of Lake Champlain in the town of Colchester.  In this locality these is a ledge sticking up in the center of a farmer’s field of jasper.  It is also found as glacial float in some of the sand & gravel deposits in the area.

Some of the marble and metamorphosed Dolostone found in western Vermont in a strip extending for the length of the state affords some fine cutting material for cabochons.

Serpentine is found in several deposits along the eastern flank of the Green Mountains extending southwards from the Canadian Border to the Massachusetts Border.  Associated with the serpentine are deposits of asbestos, soapstone and talc.  One of the best places to find soapstone is in the town of Chester.

Gold is found in the rivers and streams that drain the eastern flank of the Green Mountains.  Throughout this area placer deposits of gold have been miner for generations, and although for the most part gold is sparse one lucky miner in the 1970s reportedly hit a pocket where he recovered $2,800 worth of gold in an afternoon.

Gemstone Occurrences in Vermont

Vermont is a beautiful state, but when Mother Nature was handing out gemstones she passed over Vermont handing out very few of these stones. Finding any quality gemstones in the state is more then a little like looking for a needle in a haystack.

The Vermont Gemstone is the grossular garnet that is found at Eden Mills from the Belvidere Mine.  This mine has produced some of the best specimens of this kind of garnet that have ever been found. 

There are no extensive pegmatite deposits in Vermont although beryl crystals are found with albite in Fairfax.  Beryl crystals are found penetrating the albite at this locality.  Lake Willoughby in Orleans County is one of the few places in Vermont that does have gem bearing pegmatites.

Blue Quartz is contained in the Precambrian gneiss found in road cuts along Rt. 9 east of Bennington as you are climbing out of the valley. Smoky quartz crystals are found in the vicinity of Lowell.

Corundum has been found on Granite Hill in Cuttingsville and Shrewsbury in Rutland County Vermont according to several authorities.

Jasper is found along the East Coast of Lake Champlain in the town of Colchester.  In this locality these is a ledge sticking up in the center of a farmer’s field of jasper.  It is also found as glacial float in some of the sand & gravel deposits in the area.

Some of the marble and metamorphosed Dolostone found in western Vermont in a strip extending for the length of the state affords some fine cutting material for cabochons.

Serpentine is found in several deposits along the eastern flank of the Green Mountains extending southwards from the Canadian Border to the Massachusetts Border.  Associated with the serpentine are deposits of asbestos, soapstone and talc.  One of the best places to find soapstone is in the town of Chester.

Gold is found in the rivers and streams that drain the eastern flank of the Green Mountains.  Throughout this area placer deposits of gold have been miner for generations, and although for the most part gold is sparse one lucky miner in the 1970s reportedly hit a pocket where he recovered $2,800 worth of gold in an afternoon.

Gemstone Occurrences in New Hampshire

Aquamarine crystals (beryl) that are like those found in pegmatite pockets in New Hampshire
Photo by Gery Perant

Amethyst is found throughout New Hampshire with locations listed for practically every county in the state as well as on the Isle of Shoals off the coast from Portsmouth.  It is listed in practically all the granite quarries found throughout the State.  Amethyst is a type of quartz having a purple coloring.  The stone was originally classified as a precious stone and was numbered among the crown jewels of France.

Beryl is the official mineral of New Hampshire that is found in the many pegmatites of western New Hampshire and other granitic rocks across the state where it is found as aquamarine and golden beryl.  On a fieldtrip held in conjunction with the Gilsum Mineral Show the author was also present when emerald crystals were found in biotite schist. These were emeralds that comparable in quality with those found at Crabtree Corners, North Carolina.

Amethyst crystals like those found in New Hampshire.
Photo by Rob Lavinsky

Corundum is a mineral that often occurs in granitic pegmatites as well as pellitic limestones although we were unable to find any site specific localities in New Hampshire it is apt to be found in any silica poor rocks.  There have been reports of rubies having been found in the state.  These reports are from the Moosilauke Lake region where it is found in marble.  Corundum is often associated with kyanite in schists. Other places in the state where corundum has been found include the Belknap Mountains and the area around Wakefield. 

Fluorite is calcium fluoride used primarily as flux in the steel making process that although it is too soft to be used as a regular gem is nonetheless faceted, cut into cabochons and used as a decorative stone under circumstances where it will not be subjected to wear and rough handling.  Fluorite can be found in southwestern New Hampshire around the town of Westmoreland where it was mined at one time for flux.  Today these old mines are a collector’s paradise with beautifully colored fluorite as well as several other minerals.

Since 1985 smoky quartz has been the state gemstone of New Hampshire where it is found throughout the state.  One of the best localities for collecting smoky quartz is located in the national forest just outside Conway where it is found in rotted granite in some aggregate quarries. 

The mineralogy collection at Harvard University contains over 200 specimens of topaz crystals that were collected on South Baldface Mountain in Chatham.  Topaz is a common rock forming mineral that is often mistaken for quartz.

Tourmaline is found in the many pegmatites of New Hampshire, and it was just over the border in Maine where the fabulous find was made at Newry Maine in 1972.  Pegmatites are found in many areas of the state, but are especially prevalent in Carroll and Grafton counties.  There is a feature called the Bronson Hill Anticlinorium that is thought to be the ancient island arc that is associated with the Taconic Orogeny of Western New England.

The best place to get information about gems and gemstones is from one of the many rock shops found throughout New Hampshire.

Gemstone Occurrences in Maine

An example of carving grade tourmaline from the Dunton Quarry strike in Newry Maine.
Photo by Rob Lavinsky

There are many gemstones found in the pegmatites of Oxford County in western Maine including beryl, topaz and tourmaline, Maine’s state gemstone.  This is almost enough to make you cry, one writer describes the destruction of 225,000 carets of chrysoberyl in a blast in a pegmatite near Paris, Maine, the same writer also describes twinned crystals of this mineral weighing up to 120,000 carets that have come from the same locality.

The oldest gem mine in the United States is located on Mt. Mica an LCT Class of pegmatite in Paris the same quarry is also the second oldest known deposit of elbaite in the United States after its initial discovery at the Clarks Ledge Quarry in Chesterfield, Massachusetts. Elbaite is another name for colored tourmaline.  The Mt. Mica deposit has several other firsts including the discovery of the first rose quartz in the world.

Morganite beryl another gemstone found in Maine
Photo by Gery Parent

In the fall of 1972 a monstrous tourmaline pocket was found in the Dunton Quarry of Newry on a spur of Plumbago Mountain.  This pocket is legendary in the annals of gem mining as it yielded more then $8,000,000 worth of gem and specimen quality tourmaline.  The haul was so large the discoverers had to buy an abandoned bank building in Mexico where they stored the gem grade tourmaline in the bank vault and the specimen grade in the basement.

So important are the pegmatites of western Maine that there is a weeklong event held at the Poland Mining Camps called the Maine Pegmatite Workshop every year for the past ten years. In 2011 the workshop started on May 28. Further information about the Pegmatite Workshop can be found on their webpage.

A crystal of clear topaz
Photo by Rob Lavinsky

Tourmaline isn’t the only gemstone found in Maine there are many others.  One of these was the deposits of amethyst that came from Deer Hill in Stow that is now closed to the public.  Here the amethyst came from three quarries the Deer Hill Mine, the Nevel Mine and the Intergalactic (Eastman Ledge) Mine.  The Intergalactic Mining Company is presently mining for blue aquamarine crystals.  Aquamarine is another gemstone that is often found with tourmaline in pegmatites.

Topaz is another gemstone found in Maine with the deposits of Stoneham containing the only sizable crystals in the state.  This is a stone that is often confused with clear quartz, but glistens more when struck by sunlight.  Clear and smoky quartz crystals often accompany topaz in the states many pegmatites.  Transparent smoky quartz is often called smoky topaz or Spanish topaz if it has been heated assuming a yellowish tint.

A Maine amethyst point from Deer Hill in Stow
Photo by Rob Lavinsky

Along the banks of the St. Croix River in Perry one can find agates that have weathered from the basalt flows that are also along the river.  These basalt flows also contain native copper that was observed by the author on a collecting trip to Perry in the 1960s.  Agates are hard to see unless they have been wet by water that really makes them stand out.  The deposit also contains chalcedony and jasper.

An agate like those found at Perry along the St. Croix River
Photo by Hannes Grobe

Jasper can also be found on Jasper Beach in the district of Machias that is called Starboard along the coast right below the radar station.  The beach here is a shingle beach of rhyolite with some jasper mixed with the rhyolite stones.

There have been reports of black jade coming from the river that flows through Farmington.  If this is true it is one of the few reports of jade on the east coast.  The link for the Farmington locality also contains an extensive list of Maine minerals and their localities.

Literally there are hundreds of localities in Maine where gemstones can be found the best advice is to buy a book about the many collecting localities in the state from one of the local rock shops.

Gem Bearing Cavities in Pegmatites

Cavities in rock.
Photo by Ustill

Just about any kind of rock can have cavities some pegmatites are particularly prone to this feature, and it is in these cavities that most gemstones are found. There are many causes of these cavities, but one of the most common is a gas bubble. In many pegmatites cavities can also be formed by a lack of sufficient magma to completely fill the space the pegmatite is occupying.

Cavities are found in pegmatites generally come from one source that is the lack of sufficient material to fill the pegmatites solid. Some of these cavities are quite small and are measured in millimeters. Larger ones are measured in centimeters, and still larger ones are measured in meters. The latter are the most uncommon form of cavity. When they are found in the process of gem mining they often become legendary containing several million dollars worth of gemstones.

Rubbilite tourmaline crystals found in a gem bearing cavity in pegmatite.
Photo by Rob Lavinsky

A cavity that has not been affected by Earth movements grows a fine crop of gem crystals that are attached to the matrix. These crystals are often covered with a fine layer of clay that forms from the last of the mineral bearing solution in the cavity. One might say from the leftovers. Less than one in ten of all the cavities that are found are of this variety. Originally these pegmatites were under considerable pressure as they were formed several miles beneath the surface of the earth. As they were brought up to the surface of the earth by the process of erosion they lost this initial pressurization through the process of a diffusion of their internal gases through the pores in the rock.

Beryl, Cassiterite and Muscovite from a pegmatite cavity.
Photo by Rob Lavinsky

It's the same cavity is fractured by Earth movements so that it loses its internal pressurization crystals that it contains are shattered, and the fragments fall to the bottom of the cavity. Another feature of this type of cavity that is now open for the atmosphere allowing it to be filled with clay that accumulates in the cavity from sources found on the surface of the earth.

Finally, some cavities that remains sealed from the atmosphere are visited by a later type of mineral bearing water that causes the gem crystals inside him to be etched away partially or wholly.

These cavities are known by many names including cavity, geode, pocket and vug.

How most Colored Gems are Mined

Artesinal gem miners in Africa using traditional mining techniques.
Photo by Laura Latrigue 

Most people think that a mine is some kind of huge excavation in the ground or a series of deep tunnels that are served by the use of large equipment including 400 ton haul trucks to bring the ore to the mill. This is hardly the kind of mine describing most colored stone operations these are artisnal in nature and have hardly changed since biblical times.

The miners use as their primary tool a conical device that resembles a gold pan with a gently sloping bottom that ends in a point. The same device is also covered with small holes following easy entrance of water. This device has many names, but at least in one country where it is still used it is called the “Batik.”

An example of a rough lavender sapphire from an alluvial deposit.
Photo by Rob Lavinsky 

In use this device is filled with gem bearing gravel and then is pumped up and down in the water allowing heavier minerals to settle to the bottom of the batik. It is necessary to classify the minerals by size before being placed into the batik. Another common name for this device is the jig it because of that takes place while it is in use.

The mining takes place in the sand and gravel deposits found in association with some local stream. The gemstone deposits are usually found in close proximity to the bedrock even as gold is because most of the minerals that are classified as gemstones have a specific gravity ranging from 4 to 5 that the jigging action causes these stones to migrate to the bottom of the batik.

Sometimes the miners excavated to the gravel for 20 or more feet to reach the level of the richest deposits. Although gemstones are usually found in country that is underlain by a special type of gneiss containing the mineral cordierite like that found in the gem bearing areas of Madagascar and Sri Lanka. There is even a deposit of this special gneiss that is found in Connecticut in a narrow band extending northwards from Guilford. It is also found throughout areas that have been highly metamorphosed. It doesn't take this kind of rock to produce gemstones because they are like gold; they are where you find them.

In use once the batik has been jig up and down in the water long enough for the gemstones to settle to the bottom its top is covered with a plank and the batik is turned upside down on the plank so the gemstones are now all on top of the heap. They are then inspected for gemstones that are recovered, and the balance of the stones in the batik is discarded.

Using this method more than 50% of the colored stones that are in the jewelry trade are recovered using this method. You can make a pretty effective batik from a colander that you can buy in a kitchen supply store that is just about as effective as a batik. The most important thing that you can easily learn is what the various gemstone rough looks like.

In these times where gold is looked upon as a new measure of value it should be remembered that as far as concentrated wealth goes there is nothing that can beat gems for a very high value. Some of these gemstones are worth more than $20,000 per carat, and a caret only weighs 1/5 of a gram.