Microscope enlargement

[Daniel Fischer]

Hello! I tried to look at a texture of a rock under a microscope to see if it's a fossil and I realised that I have no idea what's the right enlargement to see the unick texture that bones have. 

If anyone knows what is the right enlargement to see the texture of a bone under a microscope please tell me.

[Mediospirifer]

Let me say first that I'm not an expert with fossil bones. I do have a few pieces, and can offer some help.

 

A lot of the texture of bone is visible to the unaided eye, or with a hand lens. I use a magnification visor of the type made for model railroad building, and that's enough to identify bone. It's not labeled with the magnification power, but I think it's 7x.

 

Here are a couple pieces of a fossil bone fragment from the Peace River, in Florida. This shows several textures typical of bone. I've outlined some key areas in different colors. Note that this is a fairly recent specimen, not more than 20 million years old.

 

Red: Holes and channels where blood vessels once passed through the bone.

Green: Typical bone interior. When living, this was spongy tissue, and rich with blood vessels.

Yellow: Weathered bone surface. Notice that it is slightly rough. This is the surface that is least distinctive compared to, for example, a water-worn piece of limestone.

Blue: Unweathered surface. This piece is smooth, although the areas covered by cartilage in life are usually porous.

 

 

 

 

 

 

Here's a cut and polished piece of mineralized dinosaur bone. I think this piece is a section of the spongy interior of the bone that has been replaced with jasper. The harder, bony bits will have more uniform structure with layers. It's possible to mistake a piece of "chunkosaurus" for petrified wood, until you've seen enough examples of both to recognize the differences.

 

 

 

Not all (or even most) fully mineralized bones are this colorful, but interior pieces should all show similar structure. 

 

Good luck, have fun with the search, and don't hesitate to post your finds in the Fossil ID section if you're unsure of what you have. 

 

[Daniel Fischer]

Thank you very much for the reply, I am straggling with a rock that is probably not a fossil but it might be. For now I don't have the supplies to cut it and see the texture inside and the texture on the surface of the bone/rock is similar to the texture of other fossilized bones (like yours) but not enough to determine that this is a bone so I figured my only option is to look at the microscopic texture of my rock/bone. This is why I am looking for the right microscope enlargement that will allow me to see the microscopic texture although it might not even be possible with my microscope.

[ThePhysicist]

13 minutes ago, Daniel Fischer said:

Thank you very much for the reply, I am straggling with a rock that is probably not a fossil but it might be. For now I don't have the supplies to cut it and see the texture inside and the texture on the surface of the bone/rock is similar to the texture of other fossilized bones (like yours) but not enough to determine that this is a bone so I figured my only option is to look at the microscopic texture of my rock/bone. This is why I am looking for the right microscope enlargement that will allow me to see the microscopic texture although it might not even be possible with my microscope.

Like @Mediospirifer said, post any suspect fossil, and we'll do our best to help you.

 

Generally, bone can be determined by the naked eye. There are interesting microscopic structures to look at, and for the purposes of identification, virtually any magnification will do - I'm sure the microscope you have is fine. What magnifications does it have? 10X, 20X?

[Mediospirifer]

Here's another image (of a different specimen), taken at 20x. 

 

 

At the top of the image is the weathered bone surface, with a trace of paler matrix that highlights the porous structure. That's fairly characteristic of bone. (Okay, the top of the image is the wooden table that I have things set up on. The bone is the darker brown. That's probably obvious, but sometimes pictures can be confusing!)

 

A little lower in the image, the next distinctive band is the clean broken surface of the bone. You should be able to see the growth layers. Below that is a gritty layer of sand that infilled the center of the bone, and the bottom of the image is the porous interior surface.

 

What kind of microscope do you have? If you can fit your specimen below the lens, you should be able to see something interesting. Try it on low power, and see what you see.   One thing I've noticed with my microscopes is that the best photo never quite captures the full three-dimensional quality of the fossil. It almost always looks better when viewed directly. The right lighting can help a lot, too--a bright light angled from the side will help show the 3D structure by highlighting the shadows.

 

Also, what does you specimen look like? How big is it? If it's an amorphous lump, you might try chipping off a tiny bit to see if the layered structure is present. Assuming you don't mind a little damage to determine what the rock is. That's up to you, of course!

 

Have fun! 

 

[Mediospirifer]

I took a quick look through my optical microscope at some highly-worn bone pieces, and I can see the layers and the fine pore structure clearly at 10x magnification. At that power, you really can't mistake bone for ordinary rocks. 

 

[Daniel Fischer]

1 hour ago, Mediospirifer said:

I took a quick look through my optical microscope at some highly-worn bone pieces, and I can see the layers and the fine pore structure clearly at 10x magnification. At that power, you really can't mistake bone for ordinary rocks. 

 

I think I am missing something again, how do you have a ×10 magnification on an optical microscope? Isn't it sopoused to be a few hundreds?

[Sagebrush Steve]

5 hours ago, Daniel Fischer said:

I think I am missing something again, how do you have a ×10 magnification on an optical microscope? Isn't it sopoused to be a few hundreds?

You don’t usually need a high power monocular microscope, ideally you want one with adjustable magnification of between about 7 and 40 power.  For an optical microscope, a stereo microscope is what you want.  I’m not as familiar with digital microscopes but there are plenty of threads on this forum that talk about them.  Just search for digital microscope.

[jpc]

If you are just looking for a microscope to be able to see bone textures, that is a very expensive way to do it.  Get yourself a GOOD magnifying glass, not a Disney World souvenir type (yes, we have them  at my museum gift shop too... useless).  

[Goldkaiser]

Look on Amazon and you can get some really good and cheap iPhone clips which magnify up to 100x.

Been very useful for other things so if your interested in microscopic pictures then I definitely recommend it.

Below is a crocodile tooth from the Cretaceous on the Isle of Wight I just took with it.

 

  

[Mediospirifer]

9 hours ago, Daniel Fischer said:

I think I am missing something again, how do you have a ×10 magnification on an optical microscope? Isn't it sopoused to be a few hundreds?

 

My optical microscope is a Bausch & Lomb Stereozoom 4. That's a stereo microscope with a magnification adjustment that ranges smoothly from 0.7 to 3.0. The full magnification is the selected position on that dial multiplied by the ocular power (in my case, 15x, but I could get oculars with different ratings if I needed higher magnification). So my available magnification range is 10.5x to 45x.

 

It sounds like you have a monocular microscope for viewing slides. That's certainly useful for applications where you need high power, but that's not usually the case for paleontology (unless you're looking at fossilized diatoms or pollen grains). 

 

If you have a craft supplies store near you, look to see if they carry magnification visors. That or a jeweler's loupe should fill your magnification needs, unless you get hooked on microfossils.   The visor is less powerful than a loupe (1.5x-3x, depending on the visor model, vs. 7x or more for a loupe), but the loupe is more difficult to use. 

 

I recommend that you look around, see what's available (and affordable), and experiment with what you find to see what works best for you. If you're really into microscopy and want to put your fossils under the microscope, look around for a secondhand one as a starter scope. And have fun with it. 

 

[Sagebrush Steve]

On 4/20/2021 at 8:04 AM, jpc said:

If you are just looking for a microscope to be able to see bone textures, that is a very expensive way to do it.  Get yourself a GOOD magnifying glass, not a Disney World souvenir type (yes, we have them  at my museum gift shop too... useless).  

Yes, but the advantage I have found with a stereo microscope is that it is very helpful when I need to remove wood splinters or cactus spines from my fingers.  Those are times when money is no object 

Edited April 22, 2021 by Sagebrush Steve

[ynot]

The amount of magnification would be dependent on what structures You want to look at, the smaller the structure the more magnification needed.

The best way to know what too look for is to compare with a known piece of bone at the same magnification.