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INDEX
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The Quartz Balls of Fundy
Part I
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The late Jurassic basalt cliffs of the Canadian Bay of Fundy, a geographical subunit of the Gulf of Maine, have long been noted as a collecting area for gemstones of the quartz persuasion (agate, jasper, and, more rarely, amethyst) as well as for zeolite
minerals. Last summer, though, my friends and I discovered and excavated (to be strictly truthful, they discovered, and I helped excavate) a deposit of quartz in a form
which, a year after the event, and after considerable publicity, does now appear to be unique in the world. These quartz aggregates are made up of radiating crystals in occasionally near perfect unsupported spheres. Generally speaking, only the crystal
terminations stud the surfaces sphere surfaces. Some of the spheres appear to have formed entirely as floaters, that is, having no discernible point of attachment. I'll get to these specifically in a moment, but first, a bit of background.
The pedigree of the Bay of Fundy quartz in its gem form extends back almost four centuries. In his voyage of 1604, the early French navigator Pierre de Guast, the "Sieur des Monts" was so taken by the amethyst he collected on its shores that he took some
back to France, had it cut and set by a Paris jeweller, and presented it to King Henry "Paris vaut bien une messe" IV as a token of his loyal esteem and an indication of the riches to be found in the new world. Both the Canadian geological pioneer Dr.
Abraham Gesner, the North American inventor of kerosene, and his rival Dr. Charles T. Jackson the "State Assayer of Massachusetts" in the mid 19th century wrote in glowing terms of Bay of Fundy gems "rivalling any to be found on the banks of the Rhine".
Later in that century, at least two Bay of Fundy islands were acquired by jewellery companies as potential sources of agate rough. While often of exceptionally fine quality, the Fundy agate however could not match the vast and recently discovered supplies
from Brazil for commercial use. Fortunately for collectors perhaps, no commercial industry thus ever took root. In "Gemstones of North America", John Sinkankas lists 13 separate Bay of Fundy localities where quartz gems may be found today.
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Left, two cobbles of "porcelain agate" from Five-Islands, about 15 miles east of Parrsboro. These were collected about 30 years ago. Folklore has it that this vein has since eroded away and such agate can no
longer be found. Top right, flame agate from Bass River, another 15 or 20 miles east of Five-Islands, bottom right, agate from Two Islands, about 4 miles east of Parrsboro.
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Associated with the quartz is a wide variety of zeolite minerals. Although I can't say whether the statement is accurate I have often heard it said (albeit locally) that the stretch of cliffs between Wasson Bluff and Swan Creek on the North side of the
Bay near Parrsboro yields some of the world's best specimens of chabazite. Stilbite abounds and is the provincial mineral of Nova Scotia; analcime is common, sometimes found in milky larger than golf ball crystals and more commonly in clear crystals up to
grape size. At one location the analcime crystals lie enclosed within "Curly Kate" cushions of felted natrolite fibres. Calcite is abundant, most dramatically perched on carpets of stilbite in clear honey yellow rhombs occasionally as big as 2" on a
side, sometimes containing phantom crystals; also as delicate dogtooth spar encrusting assemblages of chabazite, stilbite, heulandite and occasional native copper.
The North Mountain Basalt flow which hosts these minerals was deposited along a rift zone ca. 190 million years ago during the initial breakup of the supercontinent Pangaea. The flow extends in an almost unbroken 200 km stretch along the southern shore of
the Bay from Brier Island to Cape Split in Nova Scotia; it runs beneath the Bay and surfaces again on the opposite shore in smaller exposures at Cape d'Or, Parrsboro and Five Islands. Grand Manan Island in the Province of New Brunswick, just off the tip
of Maine, is a further exposure likewise hosting agate, amethyst and zeolites. Three major units are distinguished, of which the middle one is amygdaloidal while the lowermost, almost 2,000 cubic kilometres of it, ranks as one of the most voluminous
single lava outpourings on the face of the earth. Interestingly enough, the basalts of the Moroccan High Atlas Mountains are chemically indistinguishable from the North Mountain basalts of the Bay of Fundy. In fact, at the time of eruption, the two
locations were only 300 km apart. Which suggests that Morocco also might be a fruitful locality to prospect for agates, amethyst and zeolites, except for the absence here of two critical Bay of Fundy collecting aids - namely, the world's highest tides and
Canadian winter.
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Click on the image to the right for a larger (93K) map of the Bay of Fundy. |
The shape of the Bay acts as a natural funnel-cum-resonator to amplify tidal flow. At Burntcoat Head, Nova Scotia, the difference between high and low water at maximum tides has been reliably measured as 16 metres. That's 63 feet. At another nearby
location indications are it may be as much as 16.6 metres or 65 feet. At low tide, at any of the many fishing villages you'll see boats which at high tide floated on fifty or more feet of water now lying flat on the mud bottom. Twice a day, on each tide,
100 cubic kilometres of water move through the Bay - more than the daily discharge of all the rivers in the world combined. Such tides generate corresponding currents, up to 14 knots (16mph) off Cape Split, where large ocean going ships have been driven
backward despite engines churning at full speed ahead.
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| Low Tide at Parrsboro. For an idea of scale, my collecting friend Tim Rayworth, walking away from one of the lobster boats, is 6'3" tall. |
High Tide at Parrsboro. |
Combine that with Canadian winter's multiple frost/thaw cycles which split the cliffs from above and its ice pans which plough at them from below and you have an environment which is remarkably active geologically speaking. Even in summer, but
particularly in spring when the frost is coming out of the ground, massive rock falls crash from the cliffs to constantly expose and eventually bring down mineral deposits which waves and ice then quickly obliterate over the following season or two. The
effect upon one's knees of a several hundred ton rockfall crashing down within sight of where one happens to be collecting is not soon forgotten. Thus there's always fresh material to be examined, preferably quickly, since nothing stays around for very
long. In fact, the shoreline is never quite the same from one week to the next. This, for collectors, is also a benefit, for where no amount of chipping with man's puny chisels and Estwing hammers can equal the bulldozing of nature itself, there's little
incentive to "protect" seacliff mineral occurrences. But lest this sound all too forbidding, in twenty odd years of collecting I've only witnessed two such falls, and have only been hit on the head by a falling rock one single time (knock on wood!) and
that one was due purely to my own stupidity. But that's another story, albeit a funny one.
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Bay of Fundy zeolites. Above, chabazite with dogtooth spar from Swan Creek near Parrsboro; the dogtooth spar mantled with native copper. On the right, chabazite from the same locality, encrusted with dogtooth spar. The brass scale bar is one inch long,
the groove is 1 cm from the end.
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In the past few years, we've gathered a fairly active group of collectors here in the small city of Moncton, New Brunswick, just over an hour's drive from the cliffs. Often, when collecting en groupe I've pointed out that people collecting along cliffs
usually tend to collect upwards. They try to get up to what's out of reach. But seldom do they think about collecting downwards, of digging to follow a vein which may well continue beneath the gravel underfoot. That becomes important later on in the
story. With all those cliffs close by, our own collecting tends to be more in the "go out and dig" use of the word, than in the "order them systematically in the display case" sense. On any given weekend as soon as the snow is gone you'll likely find at
least one or two of us scouting the cliffs. In fact, if there's a warm winter weekend you'll find us there too, because that's the very best time, offering the most recent rockfalls, and the fewest recent visitors.
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"Black Rock", about 5 miles east of Parrsboro, at close to high tide. On the opposite shore is the Blomidon Peninsula with Cape Split at its end. Diificult to access except by boat, the shores beneath these steep cliffs offer correspondingly good
collecting. In general, it is this shore, rather than the Parrsboro side of the Bay, which offers the better collecting, for
here the basalt is much more extensive.
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Yours truly, hacking and hewing. In the background, "Two-Islands", one of the thirteen Bay of Fundy collecting localities mentioned in John Sinkankas' "Gemstones of North America".
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Now that you've been introduced to the Bay of Fundy, the story continues in next month's Eclectic Lapidary with a description of the actual quartz ball find!
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Left, a quartz ball "twin", right, my favourite of them all - the almost perfect pineapple.
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A selection of smaller quartz balls and radiating aggregates, showing some of varieties of form.
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Copyright, 1998 by Hans Durstling
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Hans Durstling is a freelance writer, jewellery maker and stone cutter living in Moncton, New Brunswick, Canada, near the zeolite, agate and amethyst collecting areas on the Bay of Fundy. His stories, reviews and commentaries have appeared in Canadian
Geographic Magazine, The European, Toronto Globe & Mail, Canadian Mineralogist, Mineralienwelt, Rock & Gem and many others. He now works primarily in corporate & industrial writing explaining complex scientific and technical products and processes to
layman readers, and writing & narrating corporate & technical videos. A considerable portion of his time is taken up with the constant battle to keep minerals and gems ("the hobby that got out of control") from taking over entirely.
Hans can be reached at sinico@nbnet.nb.ca.
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