Thread: Occlusions vs. Inclusions/Naturals/Synthetics

The rocks we are concerned with are mainly sedimentary - ie, particles laid down in water over a vast number of years, hardened by induration or some other metamorphic process, and either brought to the surface or mined. Who knows what was in the air at the time of their formation? Particles of all sorts from volcanic eruptions, silty run-off from vast distances away during flooding, etc, etc. So the elemental particles are not 100% pure - they are a mixture to begin with.

In a lot of instances you get ferric or ferrous particles in the original mix. In the case of purple slate from Wales it is not uncommon to see a green spotted or lenticular appearance as ferric reduction takes place around the original iron particle nucleus.

In others slates we find pyrites - scratchy inclusions, 'toxic' or bad if you like.

In others there was some amount of cleavage and cracking during their formation, allowing water bearing other minerals in solution to get into the cracks - the black lines and dots of manganese oxide inclusions in yellow coticules are an example, although harmless or benign, of this type of inclusion.

In geology, the term inclusion is a bit 'loose' inasmuch as it means anything included. However, one type of inclusion known as a 'clast' exists in which we get bits of other, older rocks, etc, in newer rocks. To explain how this happens imagine a silty strata being laid down in a river bed. Further upstream there are rocks that have already undergone full formation/transformation. During a raging downfall torrents of water wash down bits of these older rocks and lay them on the silt layer. The silt layer continues forming for thousands of years, then is transformed itself into rock - with bits of other rock or mineral in it.

Regards,
Neil

Originally Posted by Neil Miller

The rocks we are concerned with are mainly sedimentary - ie, particles laid down in water over a vast number of years, hardened by induration or some other metamorphic process, and either brought to the surface or mined. Who knows what was in the air at the time of their formation? Particles of all sorts from volcanic eruptions, silty run-off from vast distances away during flooding, etc, etc. So the elemental particles are not 100% pure - they are a mixture to begin with.,,,,,,,,,,,,,,,,,,,

Neil

I totally agree Neil & one cannot understate the effect that Dinosaur Flatulence had on forming some of our favorite finishers; take the coticule for instance, put yourself in a small room & slurry it for an hour or two. You'll see what I mean,,,

Originally Posted by Hirlau

I totally agree Neil & one cannot understate the effect that Dinosaur Flatulence had on forming some of our favorite finishers; take the coticule for instance, put yourself in a small room & slurry it for an hour or two. You'll see what I mean,,,

You mean you have coprolites in your hones?

Rocks are always being recycled. It's all part of the weathering process on our plant. Whether it's through sedimentation at the surface or what goes on deep in the earth it's a continual process. When you're dead and buried you may become part of that process too.

Remember, there is a difference between rocks and minerals with rocks being collections of minerals. Minerals are relatively homogeneous like Quartz for instance which is SiO2 while Granite for instance is a Rock which is made up of Quartz and Feldspar and Mica and other things for good measure thrown in.If you saw some Quartz with enough magnification you would see all the actual hexagonal xtls all nicely arranged within the matrix. If the growth conditions are perfect you have the outward expression of that with a nice looking quartz xtl like you see in books. Rocks are just a mass. Back in the old days in the Petrology Lab we would slice rocks and grind them down to paper thinness to make a thin section and look at them in a polarizing microscope and the different minerals could be easily observed.

So depending on what your hone is and what it's physical properties are and the chemistry is you can have all sorts of things going on inside your hone. Some good and some bad.

Excellent info in here.

I think this is why I (and maybe others too) am fascinated with natural hones for more than just their ability to sharpen metal. The geological processes may be well-defined but those random little inputs to the process over time and space can and do produce some spectacularly interesting rocks.

James.

Originally Posted by Hirlau

I totally agree Neil & one cannot understate the effect that Dinosaur Flatulence had on forming some of our favorite finishers; take the coticule for instance, put yourself in a small room & slurry it for an hour or two. You'll see what I mean,,,

The thing is, my dear Hirlau, that fossilised poo, aka coprolites, does not smell!

So, I put it to you that if you sit in a small room and smell a characteristic odour you imagine is coming from your hone, the chances are that you need your hearing tested and/or a change of underwear!

To be serious for a moment (and placate the Great & Wise Oz) this does have a small bearing on razors.

In the late 1820s Peruvian guano (phosphate rich bird droppings, partly digested fish and bird skeletons) were found to be a fine source of fertiliser. Enterprising individuals imported it by the boatload and fortunes were made. Eventually the cost became prohibitive and cheaper alternatives were sought.

In the 1840s on the Uk coast at Felixstowe and all along the mouth of the River Orwell a seam of coprolites was found. It was so large and extensive that whole long-lived industry grew up based on its use as agricultural fertiliset by virtue of its high phosphate content.

But where do razors come into it, I hear you cry. The answer lies with the refuse of Sheffield's knife and razor industry, namely in the waste arising from bone handles and scales. The cuttings were buried until someone noticed they made plants grow better, then around 1830 a bone meal, powdered bone and burnt bone based fertiliser industry grew up.

Demand soon outstripped supply, and Britain scoured the world for old bones. Boat loads of mummies from Egypt were ground down. Once, a burial ground for mummified cats and other pets was found in Egypt, the enterprising finder selling the lot, around 80,000, to the UK.

All things are interlinked, it seems...

Regards,
Neil

I dunno Neil, that link is tenuous at best. Not sure you're gonna fool Oz with that, he's quite sharp.

On an unrelated topic, I recently discovered a vein of naturals down my back yard. I'm gonna call them "Poo-ringians" because they are soft and have sort of a brown-blue colour like their German namesake. No need for water, they are already kind of wet. Actually, they may be better used in paste form ...

James.

Some really great info and discussion going on here, fellas. I really appreciate the posts

You're welcome Siguy,,,

I'm just glad my vast wealth of knowledge on naturals helped out,,,

Originally Posted by Jimbo

I recently discovered a vein of naturals down my back yard. I'm gonna call them "Poo-ringians" because they are soft and have sort of a brown-blue colour like their German namesake. No need for water, they are already kind of wet. Actually, they may be better used in paste form ...

James.

First I have been following this thread intensely and thank those who have contributed there accumulated knowledge with us, great stuff guys.

On to James,
I have a strop for that and I will send it to John for testing, please also submit your sample to Attn: Hirlau at.........

Originally Posted by pfries

First I have been following this thread intensely and thank those who have contributed there accumulated knowledge with us, great stuff guys.

On to James,
I have a strop for that and I will send it to John for testing, please also submit your sample to Attn: Hirlau at.........

Pat,

That would be sent Attn: Hirlau, the Wise