Jet ( Lignite ) Qing Dynasty 1821-1850

[George]

  I see this on many jet examples online like the Christies bottle from above. 
  I would want to place some degree of a "soft category" label on that material. Compared to others like mine that show no signs would certainly be on the outer edge of a "hard category", a higher grade, compacted with no inclusion pitting.

[George]

Tom, Charll and all... Could sure use a thumbs up or down if the above makes any sense for possibly separating hard and soft..
 

[Pat - 查尚杰]

I can't help you on this one George

[George]

I can't help you on this one George

Thanks Pat...

[Joey Silver / Si Zhouyi 義周司]

I'm sorry, George. You lost me after "Imagine". 

Best,
Shabbat Shalom,
Joey

[George]

I'm sorry, George. You lost me after "Imagine". 

Perhaps you were not the only one...  Sometimes I tend to over do what could have been just simply stated in a short paragraph.

I removed the confusing image, and simply showing a more porous example of what might be thought of as softer Jet .

[Joey Silver / Si Zhouyi 義周司]

Dear George,

       One thing that used to amaze and confuse me in Israel, was people trying to 'reinvent the wheel'. Of course, starting from
'A' again, could give insight. But many times it was wasting time that could have been better spent extrapolating from the already discovered point.

       We can't be the first collectors to discuss the hardness of different types of Jet and try to quantify 'softer' and 'harder' Jet.
Is there any existing mineralogical literature which discusses this?
Best,
Joey

[George]

       We can't be the first collectors to discuss the hardness of different types of Jet and try to quantify 'softer' and 'harder' Jet.
Is there any existing mineralogical literature which discusses this?

I did my best to search, but found nothing.. The best organic structure coming close that I was able to find for comparison was a microscopic structure for coal.

[Joey Silver / Si Zhouyi 義周司]

So maybe we ARE the first collectors to discuss this! 
To boldly go where no other collector has gone before... (I'm a Trekky from way back)   
Best,
Joey

       We can't be the first collectors to discuss the hardness of different types of Jet and try to quantify 'softer' and 'harder' Jet.
Is there any existing mineralogical literature which discusses this?

I did my best to search, but found nothing.. The best organic structure coming close that I was able to find for comparison was a microscopic structure for coal.

[Wattana]

Dear Star Trekkers,

I am only aware of ONE material which is referred to as "Jet". It comes from ONE particular genus of tree*, that lived several hundred million years ago*.
[*I can be more specific on both these points once I get home tonight.]
Anything else is carbonized wood, coal, or something in between, and not generally classified as jet.

In Northern Vietnam they carve wonderful sculptures out of a material that looks like jet with a slightly gun-metal sheen to it. It is in fact a high grade of coal.

Tom

[George]

One test I found is from Wikipedia tells to authenticate, "when rubbed against unglazed porcelain, true jet will leave a chocolate brown streak".

Tried this with mine, and sure enough, confirmed by a nice brown streak ..

Also reading that "hard jet is the result of the carbon compression and salt water; soft jet is the result of the carbon compression and fresh water". 

Your tree mentioned is a Araucariaceae apparently worldwide from the Jurassic and Cretaceous periods.

[Wattana]

Thanks George,

Yes that's the tree! I didn't know about the salt water / fresh water variance. Very interesting. Is it really softer, or just crumbles more easily?

Tom

[George]

Is it really softer, or just crumbles more easily?

What comes to my mind Tom, is that soft ( even microscopic ) equals porous ( less compacted ), pitting/pockets, likely because of being pressed in fresh water with more H2O than salt water. I would guess it would take a really porous and poorly compacted sample to be crumbly.. 

[Wattana]

You may be right. I am more familiar with the type of jet whch takes a high polish so it looks quite glassy. It was very popular as paste jewelry in Victorian England.

[Joey Silver / Si Zhouyi 義周司]

I did not know that Jet is fossilized Norfolk Island Pine or a relative (Araucaria family).
Best,
Joey

[Wattana]

I did not know that Jet is fossilized Norfolk Island Pine or a relative (Araucaria family).

Dear Joey,

Where did you read that? I understood Araucariaceae to be a wide family of primitive trees loosely related to modern-day Chile Pine / Monkey Puzzle, and Norfolk Island Pine, but not exclusively the latter.
My apologies if that is what you meant.

Best,
Tom

[Joey Silver / Si Zhouyi 義周司]

Dear Tom,

     No apologies necessary. I have had Norfolk Island Pines in my garden, and have turned a copy of a Chinese wine cup in NIP in Hawaii, when I was learning bowl turning (I have it in my Jerusalem home today).

     I know that Araucarias are not just NIPs, which is why I wrote, "or a relative".
But it could have been misunderstood, so your commentary is valid.
Best,
Joey

I did not know that Jet is fossilized Norfolk Island Pine or a relative (Araucaria family).

Dear Joey,

Where did you read that? I understood Araucaria to be a wide family of primitive trees loosely related to modern-day Chile Pine / Monkey Puzzle, and Norfolk Island Pine, but not exclusively the latter.
My apologies if that is what you meant.

Best,
Tom

[Wattana]

Dear Joey,
Noted!
How does the wood look? Is it similar to other pines, or more distinctive?
Best,
Tom

[Joey Silver / Si Zhouyi 義周司]

Dear Tom,

       It has a very nice colour and grain, and all the branches radiate  in a circle, so you have a series of more reddish circular 'inclusions' every so often (closer together on smaller trees, farther apart on larger.

       On my winecup, which is about 50 mm tall (close to 2 inches), there is one ring of inclusions. A friend of mine, Ron Kent, who works exclusively with NIP in his turning, once showed me a piece with rings of branches every 50 mm, which he thought rare. He reckoned that usually the circles of branches were about 75 mm minimum. On mature examples, the lines of branches are about 25 - 30 cm (250-300 mm / 10-12 inches) apart.

       My winecup has a funnel shape, a raised rim, and an indented foot. It was made ca.1990-1995, in Lanikai, Windward Oahu, Hawaii,
USA.
Best,
Joey

[Wattana]

Dear Joey,

Thanks for the additional information concerning Norfolk Island Pine. Incidentally, I have always been fascinated by this tree - how it is one of the few that go back to the age of dinosaurs, yet is only found (in its natural state) on one tiny island in the middle of the Pacific Ocean. One of nature's mysteries.

Best,
Tom