BIG powder

[George]

My son fiddles with a good microscope, so I gave him some Goex 3F and asked for a picture. Looks like coal, doesn't it? Or have any of you young guys actually seen coal? :haha:



Spence

 

[jethro224]

It does look like coal.
...Or maybe -300F. :wink:

 

[Wes/Tex]

Even looks like coal to the guy from Texas! :thumbsup: :wink:

Picked up a big, ole chunk from the Cumbres & Toltec RR yard some years ago for my brother, the train nut. Who'd a thunk it, a guy would get that giddy over a lump of coal? "Hey Santa, yah know what?!!"

 

[Alden]

Cool. What did he use for the photomicrograph and what was the (obviosuly overhead) illumination please!?

 

[54ball]

Note the yeller sulfur.

 

[azmntman]

ya I see that now, not much there. Interesting! TY for the cool pic.

 

[wulf]

Grains are all different sizes too....

 

[Brokennock]

Yep. Does look a bit like coal. Used to heat our house with a coal stove. Wood was better.
Really neat pic. Thanks.

 

[shawn_c992001]

Looks alot like coal. I mine the stuff everyday.

 

[Linc]

Yup. It looks like the rice coal I burn in my stove. :thumbsup:

 

[bpd303]

Yep looks like the coal I use in the forge, wouldn't recommend it for that though. :nono: :haha:

 

[George]

Cool. What did he use for the photomicrograph and what was the (obviosuly overhead) illumination please!?

I asked my son about his technique, and this is what he said.

The final magnification is a little difficult to calculate because of some unknown variables, but I’ve measured it empirically and found that on a 100dpi monitor it’s 75x with that objective. The background light is just the built in light of the microscope turned down real low. It appears brown because it’s a halogen bulb whereas the incidence lights are LEDs, so there’s a color difference. The picture is white balanced for the incidence lighting, making the backlight go brown. My camera is a Canon 20D attached to the trinocular port on the top of the microscope.

There are two lenses on a microscope, one right above the specimen, called the objective, the other which you look through called the ocular. This shot had to be taken with the lowest power he has because in microscope terms those powder grains are huge. He used a 4X objective and a 10X ocular for a straight magnification of 40X... then the camera and monitor increase that. You can see the background light under the stage, the round one. I believe the incidence lights he mentions are additional lights he added, which he uses for side and top light, for 3D modeling. The trinocular he speaks of is just a straight tube on top with an adapter to attach the camera, the silver tube in this photo.



Spence

 

[Patocazador]

After the war (WWII) we got a new house and it caught on fire a year later due to a faulty coal-burning furnace. Fire Dept. put it out quick. Converted to oil and all was OK.

The last time I saw coal was about 5 years ago when I ran my Boykin at a hunt test at a reclaimed coal mine in north Ala. Coal was laying all over the place.

 

[Brokennock]

This wasn't a furnace, just a stand alone stove like a wood stove, in fact, if I remember correctly, we could burn wood or coal in it. The stove we replaced it with was wood only.

 

[Blackbruin]

Not quite as shiny and even surfaced as anthracite coal but yes it looks similar! A lot of people still heat with coal here in north central pa!

 

[MSW]

cool photo ... thanks for the post!