GORMANITE FROM THE YUKON; FINALLY SAM McGEE IS WARM

 

A mixture of quartz, lazulite, and others. Width FOV ~9 mm.

On a lazy Memorial Day weekend afternoon, I had a little daydream about phosphate minerals. Lately my Blog postings have wandered all over the place but never seemed to land on phosphates. The secondary phosphates are among my favorite minerals, so I reached into my magic drawer and grabbed a box that I had been “eyeing” for several weeks—gormanite. This hydrated hydroxy phosphate is not all that attractive; however, the presence of beautiful siderite crystals, along with other microminerals beyond my skill to identify, in the specimen greatly increases the attractiveness.  Mention gormanite and siderite in the same sentence and mineralogists and rockhounds in-the-know will immediately pinpoint the locality—Rapid Creek, Dawson Mining District, Yukon, Canada. Here gormanite forms as low temperature fracture fillings in siderite-rich mid-Cretaceous sandstones (Frost and others, 2003). But perhaps the best know mineral from the area is the beautiful azure-blue mineral lazulite [MgAl₂(PO₄)₂(OH)₂]. 

Lazulite (blue), quartz, and siderite. Width FOV ~ 9 mm.
 

Lazulite crystal. Width ~ 3 mm.

Siderite crystal (center). Width ~ 2 mm.

 

 

Siderite crystals. Width FOV ~ 9 mm.

Siderite crystals. Width FOV ~ 9 mm.

Gormanite [Fe²⁺,Mg)₃(Al,Fe³⁺)₄(PO₄)₄(OH)₆-2H₂O] occurs as radiating aggregate of acicular, bladed crystals of a blue-green color (depending upon light conditions). Crystals do have a pale green streak, Again, depending upon light conditions, their luster appears as greasy to sub-vitreous to metallic to dull/earthy. Their hardness has been measured at 4.0-5.0 (Mohs) and they are quite brittle with a splintery fracture.Individuals are often transparent to at least translucent.  Gormanite forms a solid solution series with souzalite where magnesium is the dominant cation rather than iron. 

 

Gormanite sprays. Width FOV ~17 mm.

Sprays of gormanite with siderite crystals and other minerals. Width FOV ~ 9 mm.

The Rapid Creek, and associated Big Fish River localities, along with several smaller sub localities, are in northern Yukon, Canada, a locality without a coffee shop or convenience store. Oil and or mineral geologists in the late 1960s to 1980s, armed with mosquito netting headbands, were cruising around the area, and happened on chips of lazurite. This blue mineral attracted the attention of mineralogists and rockhounds and now the localities have a list of 70+ known minerals including 8+ Type Localities counting gormanite. However, although the Rapid Creek Formation is noted for the presence of well crystallized secondary phosphate minerals it is also noted for the absence of common phosphates that are a normal part of the diagenesis of iron-phosphate bearing sediments (Gunter, 2020)

Confusion abounds in describing the depositional environment of the Rapid Creek Formation. Robertson (1982), one of the first geologists to deeply delve into the  Rapid Creek mineralogy and geology, believed the rocks were deposited in a quiet near shore environment. Later work by Gunter (2020) noted the “absence of clay minerals was one of the main differences between the Rapid Creek Formation and the other contemporaneous sedimentary sequences of the eastern Canadian Cordillera. Traces of volcanic ash in the form of thin bentonite layers are widespread in the shoreline to shallow marine mid-Cretaceous sedimentary sections as far east as Manitoba. These bentonite-sourced smectite clays are not present in the Rapid Creek Formation and provide supporting evidence for the deep-water deposition of the phosphatic shales…an unusual situation since the majority of world-wide phosphatic shale sequences are shallow-water deposition.”

For gormanite: So you're a little weird? Work it! A little different? Own it! Better to be a nerd than one of the herd!    Mandy Hale

REFERENCES CITED

Gunter, R., 2020), Yukon phosphate update: https://www.mindat.org/article.php/3865/Yukon+Phosphate+Update+2020.  

Frost, R., K Erickson, M. Weier, S. Mills, 2003, Raman spectroscopy of the phosphate minerals: cacoxenite and gormanite: Asian Chemistry Letters, 7.4.

Robertson, B.T.,1982, Occurrence of epigenetic phosphate minerals in a phosphatic iron-formation, Yukon. The Canadian Mineralogist: Vol. 20, No. 2.

Robinson G.W., Van Velthuizen J, Ansell H.G. and Sturman B.D. (1992) Mineralogy of the Rapid Creek and Big Fish River Area Yukon Territory: Mineralogical Record v. 23 no.4 p. 4-47.

I have actually set foot in the Yukon, maybe 10 feet or so. I rode the White Pass and Yukon Route narrow gauge railroad from Skagway, Alaska, up to the top of White Pass, the U.S.-Canada border. We actually used part of Yukon to “turn around.” The gold loving “stampeders” continued to the Klondike in 1896-1899. Most never “struck it reach” and returned home or died. Some of these prospectors never warmed up in the cold until their final end, like my favorite Sam McGee.

The Cremation of Sam McGee

By Robert W. Service

There are strange things done in the midnight sun

      By the men who moil for gold;

The Arctic trails have their secret tales

      That would make your blood run cold;

The Northern Lights have seen queer sights,

      But the queerest they ever did see

Was that night on the marge of Lake Lebarge

      I cremated Sam McGee.

Now Sam McGee was from Tennessee, where the cotton blooms and blows.

Why he left his home in the South to roam 'round the Pole, God only knows.

 He was always cold, but the land of gold seemed to hold him like a spell;

Though he'd often say in his homely way that "he'd sooner live in hell."

 

On a Christmas Day we were mushing our way over the Dawson trail.

Talk of your cold! Through the parka's fold it stabbed like a driven nail.

If our eyes we'd close, then the lashes froze till sometimes we couldn't see;

It wasn't much fun, but the only one to whimper was Sam McGee.

 

And that very night, as we lay packed tight in our robes beneath the snow,

And the dogs were fed, and the stars o'erhead were dancing heel and toe,

He turned to me, and "Cap," says he, "I'll cash in this trip, I guess;

And if I do, I'm asking that you won't refuse my last request."

 

Well, he seemed so low that I couldn't say no; then he says with a sort of moan:

"It's the cursèd cold, and it's got right hold till I'm chilled clean through to the bone.

Yet 'tain't being dead—it's my awful dread of the icy grave that pains;

So I want you to swear that, foul or fair, you'll cremate my last remains."

 

A pal's last need is a thing to heed, so I swore I would not fail;

And we started on at the streak of dawn; but God! he looked ghastly pale.

He crouched on the sleigh, and he raved all day of his home in Tennessee.

And before nightfall a corpse was all that was left of Sam McGee.

 

There wasn't a breath in that land of death, and I hurried, horror-driven,

With a corpse half hid that I couldn't get rid, because of a promise given;

It was lashed to the sleigh, and it seemed to say: "You may tax your brawn and brains,

But you promised true, and it's up to you to cremate those last remains."

 

Now a promise made is a debt unpaid, and the trail has its own stern code.

In the days to come, though my lips were dumb, in my heart how I cursed that load.

In the long, long night, by the lone firelight, while the huskies, round in a ring,

Howled out their woes to the homeless snows— O God! how I loathed the thing.

 

And every day that quiet clay seemed to heavy and heavier grow;

And on I went, though the dogs were spent and the grub was getting low;

The trail was bad, and I felt half mad, but I swore I would not give in;

And I'd often sing to the hateful thing, and it hearkened with a grin.

 

Till I came to the marge of Lake Lebarge, and a derelict there lay;

It was jammed in the ice, but I saw in a trice it was called the "Alice May."

And I looked at it, and I thought a bit, and I looked at my frozen chum;

Then "Here," said I, with a sudden cry, "is my cre-ma-tor-eum."

 

Some planks I tore from the cabin floor, and I lit the boiler fire;

Some coal I found that was lying around, and I heaped the fuel higher;

The flames just soared, and the furnace roared—such a blaze you seldom see;

And I burrowed a hole in the glowing coal, and I stuffed in Sam McGee.

 

Then I made a hike, for I didn't like to hear him sizzle so;

And the heavens scowled, and the huskies howled, and the wind began to blow.

It was icy cold, but the hot sweat rolled down my cheeks, and I don't know why;

And the greasy smoke in an inky cloak went streaking down the sky.

 

I do not know how long in the snow I wrestled with grisly fear;

But the stars came out and they danced about ere again I ventured near;

I was sick with dread, but I bravely said: "I'll just take a peep inside.

I guess he's cooked, and it's time I looked"; ... then the door I opened wide.

 

And there sat Sam, looking cool and calm, in the heart of the furnace roar;

And he wore a smile you could see a mile, and he said: "Please close that door.

It's fine in here, but I greatly fear you'll let in the cold and storm—

Since I left Plumtree, down in Tennessee, it's the first time I've been warm."

 

There are strange things done in the midnight sun

      By the men who moil for gold;

The Arctic trails have their secret tales

      That would make your blood run cold;

The Northern Lights have seen queer sights,

      But the queerest they ever did see

Was that night on the marge of Lake Lebarge

      I cremated Sam McGee.