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Can Someone Please Help Me With This Specimen?

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Jennifer Stanley Welsh October 11, 2018 08:07PM
Okay here it goes. I did the best I could with this.

Luster - Submetalic, opaque. One side appears tarnished and mottled with goldish mineral streaks.

Streak - Silver color with shimmery luster.
Grey streak when scratched on paper.

MOHS hardness of about 5/6

Habit - Massive.

Cleavage - Poor to no cleavage at all.

Fracture - Uneven, hackly and jagged w/powdery residue.

Magnetic - No magnetism.

Weight - 1.36 grams (0.3 LBS)
3-1/2" in length
2-1/2" width
1/4 - 1" thick

Note: Jagged edges are easily bendable with a fingernail. White spot present on upper left side of specimen.

Taste - None

Location - Found in West Natick, MA, USA near Lake Cochituate.



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Alfredo Petrov October 11, 2018 08:31PM
Possibly a piece of lead from an ancient corroded bullet?

I think you have a decimal point in the gram weight that shouldn't be there - 136 grams.
Since it marks paper it must be very soft; Mohs hardness around 1 or 1.5.
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Paul Brandes October 11, 2018 08:44PM
Welcome to Mindat, Jennifer!

I'm not seeing anything in the database for the Natick area that would resemble what you have pictured. Are/Were there any sort of smelters in the area?
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Douglas Schonewald October 11, 2018 08:47PM
Jennifer,

I think it is very interesting. I suspect the yellowish stuff is slag left over from smelting the lead (which is what I believe this is based on weight). It could be a natural piece of lead (not sure if that has ever been found in that locale) but as Alfredo said it is likely something dropped by a Native American or early settler. I think it is possibly a piece of lead that was carried by one, or the other, that would be cast into bullets as need arose. Native Americans and early settlers seldom purchased pre-formed bullets. Instead they carried a few pieces of bulk lead, a small ladle, and a bullet mold in their 'possibles' and cast bullets as they had time and need. Finished bullets were carried in a leather bag much like children carried marbles in years past. The tools to cast bullets, some ticking to use as a bullet patch, and powder in a horn or flask comprised their accoutrements. It is interesting and likely we will never know if it is a 'flattened' round ball (aka bullet) or a piece of pig carried for the purpose of making bullets. If it is a flattened round ball it would make sense since a .50 caliber round ball will weigh about 176 grains when un-fired and they would lose some weight if they hit something solid. So that is a distinct possibility. Nice find.



Edited 1 time(s). Last edit at 10/11/2018 08:48PM by Douglas Schonewald.
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Bob Harman October 11, 2018 08:56PM
If found in the proper surrounding context, you may have found an old lead musket ball. They were made of lead and found in your area. More of a historical artifact rather than a mineral??? Suggest bringing it to be examined at the local historical society. They may be of help recognizing it.
CHEERS.....BOB
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Jennifer Stanley Welsh October 11, 2018 09:31PM
I don't think it's a musket ball. It's a little too big and heavy. You have to remember the weight and size of this thing is 136 grams (0.3 LBS). 3-1/2" in length. 2-1/2" width and 1/4 - 1" thick. A musket ball is roughly about 1/4 inch round which is pretty small unless I'm wrong. Also, Lake Cochituate is next to an active railroad in case that helps you guys.
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Roger Ericksen October 11, 2018 10:03PM
Based on weight and size it is still most likely a piece of lead. Since found near a lake, perhaps to use for fishing weights.
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Jennifer Stanley Welsh October 11, 2018 10:05PM
Oops sorry about that. 136 grams. Thank you for letting me know.
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Amir C. Akhavan October 11, 2018 10:47PM
136 g is very little, less than a typical smartphone.

If it is 3.5" x 2.5" x 0.5" in volume, that would make about 65 cm^3. (switching to metric system)
If this was pure lead, it would weigh about 740 g.
Even if you take into account the dents etc, it is still too light, even for iron:

136 g lead = 12 cm^3.
So a 3.5" x 2.5" lead plate of 136 g is 0.22 cm or 0.09" thickn.

The weight should be measured again :-)
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Pavel Kartashov October 11, 2018 11:17PM
I am think, that this is much more modern thing, than you suppose. :-) This is piece of ZAMAK alloy - https://en.wikipedia.org/wiki/Zamak It is lighter, harder and more refractory than usual pure lead. And it became abundant after WWII.
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Lukáš Křesina October 12, 2018 07:21AM
Amir C. Akhavan is right, 136 g is too little for lead. Fracture with powdery residue does not correspondent with lead.
This material is probably inhomogeneous - hardness 5/6, but it has grey streak when scratched on paper. On the photos I can see yellowisch grains that looks like pyrite. Pyrite is very common in graphite. So what about graphite pebble? Is it great nonsense?
Lukáš Křesina
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Larry Maltby October 12, 2018 10:56AM
For those who favor the possibility that this may be an artifact, there is some support in the history of the lake. The lake was the result of a dam built around 1850 to supply water to Boston. The area was heavily used including various industries. There was a PCB transformer explosion in 1984 etc.

See here: https://en.wikipedia.org/wiki/Lake_Cochituate
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Dale Foster October 12, 2018 11:37AM
Jennifer Stanley Welsh Wrote:
-------------------------------------------------------
A musket ball is roughly about 1/4 inch round which is pretty small unless I'm wrong.



A typical ball from a smoothbore musket can be from .58" to .75" in diameter, depending on the weapon in question.

.25 inch would be very small calibre for a firearm of the period.
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