Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. It is an important ore of tungsten. Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws. Scheelite has been synthesized via the Czochralski process; the material produced may be used to imitate diamond, as a scintillator, or as a solid state lasing medium.
Its crystals are in the tetragonal crystal system, appearing as dipyramidal pseudo-octahedra. Colours include golden yellow, brownish green to dark brown, pinkish to reddish gray, and colourless. Transparency ranges from translucent to transparent and crystal faces are highly lustrous (vitreous to adamantine). Scheelite possesses distinct cleavage and its fracture may be subconchoidal to uneven. Its specific gravity is high at 5.9–6.1 and its hardness is low at 4.5–5. Aside from pseudo-octahedra, scheelite may be columnar, granular, tabular or massive in habit. Twinning is also commonly observed and crystal faces may be striated. Scheelite streaks white and is brittle.
Hi once again fellow Hounders,
Well, my leg muscle spasms have finally eased and I can sit without leg seizures.
After getting up at 4:45AM to get to Bakersfield to hook up with the San Joaquin club, the Sierra Pelona club going by a different route out of my way, we stopped for a quick breakfast to ease the diabetics( me included), we headed for the sand shed parking lt at Greenhorn Summit and arrived slightly late finding a large crowd “patiently” waiting. After having release forms signed and being introduced to everyone being introduced it was quickly decided by Ron (the Sierra Pelona FTC) and I to divide into two groups. Ron and Mike (club president) led the first and smaller group to the Rose Quartz quarry while Lew (San Joaquin pres) and I led the other , larger group to the tungsten mine. Seems like I was basically the only one who knew the way to the tungsten mine (and I STILL took a wrong trail on the numerous side roads) but got the first batch of trucks to the dump area. It turned into batches because every few trucks got hung up on various berms (I’d only walked that trail on previous excursions) so having to hike back and forth to direct vehicles around obstacles rather than over them weall eventually made it although many vehicles chose to park on the soft shoulder on 155 rather tan chance it. Many hounders hiked in while others doubled up with high clearance 4x4s.
It was 5:00 A.M. when I woke up and made a pot of coffee, did my
usual things and headed to the shop around 6. When I arrived there
were several eagar hounders waiting there .Other hounders moised in
here and there until 7:00 A.M. Shep made it and we all (21of us)
jumped into the truck and we headed to Cindy’s for a harty
breakfeast.By quarter to eight we all were full and on our way for
some beautiful garnet epidote and rose quarts. We were a little
late. By 9:15 we all gathered at the sand house at Green Horn. There
were Rangers and cars every where.
More from Craig…
I recently moved and am still in the process of setting up and cataloguing 1000+ specimens. These photos were taken very quickly at the request of a friend. Better photos and descriptions to come. Click here to view his folder of specimens.
This is from a reader who submitted his fav specimen and a little story about it. Enjoy!
Wow, favourite? Next to impossible. My favourite mineral is Epidote, followed by Crocoite and Stibnite. But my one favourite specimen would have to be “Baby”: www.flickr.com/photos/tjflex/224994271/in/set-72157594160823741/ .
A friend of mine is a mineral dealer and went to Tuscon earlier in the year. He brought back, let’s say “a large amount of minerals”. One of the show stoppers was this Agate, which he had sitting on his kitchen table. After spending hundreds of dollars (at “good” prices) I left.
I am always open to new and interesting things and this is definitely new for me. I was checking out lapidary pictures when I came across Lisa Morgan. She is an artist that does digital drawings of minerals and I asked her a bit about what she does and she said I could post her drawings on here. Check out these creative drawings…And thanks Lisa for sharing!
i’ve had a passion for gems since I was a little girl and felt attracted to stones ever since. I have a small collection and drew the ones i couldn’t afford and wrote small explanations on each in english to describe their physical particularities (sapphires aqua marines diamonds opals…) Most of my drawing are also for sale just in case some body would like one…)
Thank you very much for paying attention and your nice word .
Thanks to scholtz at flickr for letting me use his pictures from Carlsbad Caverns! Checkout his whole series here http://flickr.com/photos/scholz/sets/72157594267632917/
I found the caverns an interesting read and now would love to check them out one day! Heres a little article about them from wikipedia.org, enjoy!
The story of the creation of Carlsbad Cavern begins 250 million years ago with the creation of a 400 mile (600 km) long reef in an inland sea that covered this region. This horseshoe shaped reef formed from the remains of sponges, algae and seashells and from calcite that precipitated directly from the water. Cracks developed in the reef as it grew seaward. Eventually the sea evaporated and the reef was buried under deposits of salts and gypsum.
Then, a few million years ago, uplift and erosion of the area began to uncover the buried rock reef. Rainwater, made slightly acidic from the air and soil, seeped down into the cracks in the reef, slowly dissolving the limestone and beginning the process that would form large underground chambers. At the same time, hydrogen sulfide gas was migrating upward from vast oil and gas deposits beneath the ancient reef. This gas dissolved in the percolating ground water to form sulfuric acid. The added power of this corrosive substance explains the size of the passageways. The exposed reef became part of the Guadalupe mountains and the underground chambers became the wonder of Carlsbad Cavern.
hit the read more button to continue:
The story was submitted by a reader, I did some research and found a couple interesting stories associated with this spot, check it out. Its a good read about the early days of prospectors and the goldrush…
THe story submission:
A Lost Geode
Almost thirty years ago I took up gold panning as a recreational/vacation hobby. I managed to luck out and was in the Princeton Gold Commissioner’s office when the clerical staff processed the cancellation of a gold claim on Granite Creek. The claim covered a kilometre (by ½ k wide) up and downstream of the confluence of Newton Creek – a small tributary of GC which in turn joined the Tulameen river, near the ghost town of Granite Creek – about ten miles downstream from the claim on NC. I got a map of the claim location and stopped at the local lumber yard to buy the makings for a small sluice-box.
The road that parallels GC to the NC and beyond was scenic for it passed through an abandoned coal mine community – name forgotten now – and we had to ford a small stream at a Provincial Forestry Campsite – about 1 ½ miles from NC. Not knowing the location of claim markers I broke a trail downstream (south side) of NC and pitched a tent on a sand bar on GC below the mouth of NC.
Did I mention I had my two boys and the dog with me so the next morning while they slept in I hiked back to the Ford Station Wagon/boat and made a few trips hauling in the sluice-box wood, some tools and other camping gear.
On one of my beast of burden hikes, from the car parked at the creek crossing, I spotted a broken rock (50 to 100 lbs). I could see lichen covered shapes that looked to me like a crystal cluster –within a broken egg-shaped-rock. I was not at that time into rocks but now that I have retired and have taken up an interest I realize that what I had seen on the edge of NC was a large geode – that today if cleaned up could be worth something. The rock was a short stone-throw from the road, less then 100 yards downstream of the Newton Creek culvert.
I spent two or three years camping and panning on GC. We found a perfectly dry double shake-roofed, hard-rock miner’s cabin within the boundaries of the claim. There was a perfectly good trail down to it, from a parking spot where the claim marker stood at a nearby bend in the road. In the warmth of summer you could stand the chill of the water for a swim/bath. I was able to use the sluice for two years running but it was too warped for the third. I did find a little nugget and still have the specs of gold and platinum that I found. There were a few fish in the stream and although not much for wide expanses of scenery, there were no bears and our only pest was a pack rat – who enjoyed rattling our pans on wall of the cabin – in which we pitched our tent.
I regretted giving up the claim when I moved back to Calgary in 1982. The guy I sort of turned it over to gave it up after the first visit, when his wife was trapped in their camper by the Park Bear, while he and the boys walked to the claim from the ford in the stream. I doubt that the road is anymore then it was thirty years ago. It could get sticky in a rainstorm but in the rain-shadow of the Coastal Range the area is quite dry in the summer and fall. Undoubtedly, the claim is claimed for the price of gold is rising again – as it was in the early 80ties. Recreational panning is still permitted any where in BC except Provincial Parks, so sniping along the streams should be OK unless you cross the path of the red-neck whose name is on the claim marker. The broken geode in and along Newton Creek road rough and tumble may still be there. I might look for it sometime when I’m passing through sometime. Hopefully, for your sake you get there before me.
So posting my rockhound pics at Flickr, I have met a lot of interesting people interested in taking pictures of Lapidary, gems, and rockhounding. They have allowed me to use their pictures on my blog and many thanks to them for that! I will be posting some of their pictures for us to view along with a link that can be clicked on to see all their pics. Check out their albums as there are great pictures there!
This picture is from Kate from New Zealand, and this is how she ended up taking it-
Helped take the 2nd year geology students on their second fieldtrip for the year. The trip is 7 days long on the West Coast out of Westport and we look at the sedimentary sequence, granites and metamorphic rocks associated with the rifting of New Zealand from Gondwana.
Thanks Kate! View all the pics from that week by clicking th elink below…
ROCKHOUNDING IN THE CALGARY AREA
It’s pretty tough being an Alberta rock hound, it’s even tougher being a broke old rock hound living in Calgary.
Then again there are a few rock treasures around and from the east side of Calgary and as far flung as the badlands of the Red Deer River. I have made a collection over the years that would impress most amateur geologists/palaeontologists and most of my collectables were picked within a hundred miles of Calgary. I have a good sampling of local Calgary gravel, which includes most types of rock in the rockhound books, except metals and precious gems. I have collected fossil wood and even bone in the local gravel but most of my fossil bone comes from the badlands and gravels around Drumheller.
My favourite gravel patch around town is the artificially deposited gravel lining of the irrigation ditch, downstream of the weir near the centre of the city and out as far as the bedroom community of Chestermere Lake, about 10 kilometres out of town. The ditch was constructed over 50 years ago and within the last twenty it was revamped and beautified by the addition of more gravel to both banks and a bike trail along its entire length. The gravel comes from either pits south of town along the Bow River or from the Beiseker deposits or both. I know the gravel is mostly from downstream of Calgary because there is Canadian Shield material included with the sedimentary material of the eastern slopes. The Laurentide and Cordilleran glaciers fought a few times for supremacy in the Calgary area and float from each were left around town to be found in the make up of the ditch liner. I like the way the weather has cleaned the ditch gravel and except for the gravel below the water level the rocks have been rain washed, I even have licked a few to get a better view. Most of the rock is unsorted pit-run, so all sizes are present and I have brought home little fragments, pebbles and even a pretty boulder or two. The ditch rock is actually owned by the Western Irrigation District – I assume this to be the Alberta Government – but I can’t say I have picked up much more then a couple of hundred pounds over the years – a couple rocks at a time. Most of the time I’m just out for the exercise – strengthening my ankles for my badlands hikes.
I have found some museum quality stuff in the ditch gravel. Tumbled Palaeozoic marine coral fossils are quite common and I have several samples of fossiliferous limestone with various sea life that when polished make good shelf curios. There are12,000 year old hardened and rounded off glacial lake sediments with snail shells and occasionally you may find a piece of river rounded sandstone with clam shells or their impressions. Some of my best pieces however, are the occasional pieces of petrified wood, which along with granite, schist and gneiss form the continental glacier’s contributions. The glacial float was scooped out of river gravels further north and mixed with our local rocks when the two great glacial masses left their battle scars on Calgary’s landscape.
My best find to date, is a fist sized carnelian agate nodule considered a one of a kind for the Bow River. I have been to the ditch several times before and after this find and can say I’ve never found any thing quite like it. The petrified wood is opalized or agatized or may be crack filled with chalcedony of some sort but never have I seen pure carnelian agate. However, it is not uncommon in Alberta, but according to local rock hounds not much has been found around Calgary . I have found some in the North Saskatchewan and Red Deer River gravels; only small fragments of course, never almost complete fist-sized nodules like my Calgary Agate. I got a write up in the June 2002 edition of the online Canadian Rockhound Magazine, for a one of a kind find.
I shouldn’t ignore the other hard stuff in the gravel that actually polishes quite well either by hand or in the tumbler. The banded quartzite from the Rockies is a favourite and granite pegmatite comes a close second. I have found some feldspar gabbros and crystals that are pretty and will pick up schist to shine back at me from my rock garden.
I could give a course in local geology sitting on a lawn chair under my big blue spruce out front. My rock garden has mostly local things in it, from rusted railway spikes to big old beasties bones. The beasties bones of course are culls from a hefty quantity of fossil dinosaur fragments that I bothered to rescue from erosion. Under my tree is dryer then the eroded slopes of Alberta’s Badlands. Besides, I’m just maintaining some of our natural heritage a little closer to my home – if it’s under my tree you’re welcome to it, one piece at a time of course.
I have an enviable tooth and claw collection and the displays within my walls are wondrous and marvellous to my eye. As I sit hear dissertating I can look up and see my crystal core, my stormy rock, my best bones and a piece of my one and only Calgary Agate. My homemade fountain trickles besides me as I type and on its ledges washed with water is a fair sampling of my collectables. I now realize that even in Calgary you can be surprised at the variety and quality of rocks a watchful eye may pick up around town. After an unusual cold snap the sun is back and the sky is finally blue. I think I’ll head for the ditch, my ankles need a tune up for Thursday in the badlands.