Cumberlandite

[CMD]

Cumberlandite is the state rock of RI. It only outcrops on Iron Mine Hill, in Cumberland, RI, and nowhere else on Earth. It has been brought up in deep core samples in Canada.
When the glacier scraped Iron Mine Hill, it picked up many pieces of Cumberlandite, and when the ice retreated, it dumped Cumberlandite in a glacial boulder train on the margins of Narragansett Bay, with the apex of the boulder train being Iron Mine Hill.



http://www.geocaching.com/geocache/G...n-rhode-island
It's also the best known meteorwrong from RI. Its' appearance, density, and magnetic properties ensures that people will confuse it with a meteorite:
http://meteorite-identification.com/...erlandite.html
Some examples:






This small glacial pebble is interesting. Picked up in the Cumberlandite boulder train, the rind or cortex shows an odd circular pit on the face seen here. It resembles an anvil stone or may have been briefly utilized as a hammerstone prehistorically. Speculative on my part, I just noticed this circular area that resembles pecking yesterday for the first time.

[CMD]

http://www.ereferencedesk.com/resources/state-symbols/rhode-island/rock.htm

"Cumberlandite is the Official State Rock of Rhode Island. This very special rock was originally named Rhodose and was identified hundreds of years ago but was renamed Cumberlandite by Wadsworth (1861). This is an extremely rare and unique stone and has significant historical and geological interest. Heavy black or dark brown rock with white markings. It is found South of Cumberland on both sides of Narragansett Bay and has not been discovered outside the state of Rhode Island. It is classed as a variety of ferrogubbro and is an porphyritic igneous rock composed of crystals white plagioclase feldspar in a finer-grained groundmass of magnetite, ilmenite, and olivine that was "stewed in its own juices". The feldspar and olivine changed to a fine-grained serpentine. It will attract a magnet and this characteristic is considered a positive means of identification. Scientists have estimated the age of Cumberlandite to be about one and one-half billion years when a small volcano erupted and 24 different minerals mixed together with molten rock and when it cooled formed a slightly magnetic rock that is iron rich. Cumberlandite is commonly mistaken for a meteorite. This is because it has intense magnetic susceptibility, its high specific gravity, and common pitted nature.
This rare ore deposit is world renown and thought to be the largest and purest body of ore in New England. It is located on a 3.7 acre parcel in Cumberland, Rhode Island 02864 near the intersection of West Wrentham Road and Elder Ballou Meetinghouse Road It is about three miles east of Woonsocket, RI, four miles SW of the NE corner of RI and one mile from the Massachusetts state line. It is the world's only known site of Cumberlandite rocks. The area is known as "Iron Mine Hill.
These extremely rare rocks were deemed sacred by the Nipmuck Indian Tribe. Cumberlandite was also used as early as 1703 for cannons, weapons and farm tools during the Revolutionary War when it was recognized as a possible ore of iron. It was mixed with hematite from the Hopkins Iron Mine in Cranston, Rhode Island and was forged by Philip Brown at Abbott's Run in Cumberland. Sometime later, John Brown of Providence, R.I., was contracted for iron used in cannons by the US Government. He used a mixture of Cumberlandite and Cranston ores and smeltered them in Easton Massachusetts.
The Iron Mine Hill outcrop, elliptical in cross section, was estimated to be approximately 1,200 feet long on its major axis, and 500 to 600 feet on its minor axis. Jackson (1840) calculated the mass of porphyrytic magnetic iron ore, 462 feet long, 132 feet wide and 104 feet high with 6,342,336 cubic feet of ore visible. It has a specific gravity of 3.82-3.88 giving it tonnage of approximately 7,641,488 tons. Jackson's analysis stated this would yield about 3,000,000 tons of ore and over 1,000,000 tons of titanium."
---------------------------------------------------------------------
Deemed sacred by the Nipmucks? I have never found the source or sources for this belief. Of course, the natives would not have missed anything in their environment. They must have been aware of this rock, but beyond that simple assumption, don't know how or if it was utilized.

[JoshinMO]

Interesting, Thanks!

[rmartin]

Never heard of it.....Thanks for the info Charlie

[painshill]

Interesting stuff isn’t it Charlie?
Geologically, it’s titaniferous magnetite melatroctolite and formed by gravitational settling of olivine, titaniferous magnetite and cumulophyric plagioclase-olivine aggregates from an anorthositic gabbro magma. USGS defines it as: “black, medium-grained, porphyritic melatroctolite (phenocrysts of plagioclase), composed of magnetite, ilmenite, olivine, plagioclase, and accessory hercynite spinel; secondary chlorite and saussurite. Abundance of magnetite and ilmenite (up to 70% of rock) results in characteristic high specific gravity. The rock is massive, but locally exhibits a flow lamination caused by the planar orientation of plagioclase laths.”
It’s age is uncertain but unlikely to be as old as 1.5 billion years though, I think. It’s part of the West Bay Esmond-Dedham Subterrane and is believed to have intruded into the Late Proterozoic Blackstone Group between 620 and 370 mya.
As you probably know, our “friend” Scott Wolter got himself all excited when he found pieces of it had been used in the construction of the Newport Tower in RI. He refers to it as “The Stone of Venus” (an attribution he seems to have assigned all by himself), in support of his belief the tower has an alignment to the planet Venus. That, in turn, he takes as proof that the tower is tied to Cistercian and Knights Templar symbolism of the divine female in the heavens, symbolized by the planet Venus (as opposed to it being a 17th Century windmill).
I’ve also never seen any reliable reference to the sacred nature of the stone as far as the Nipmuc are concerned. Everywhere this is mentioned, they seem to use exactly the same words without ever quoting the original source. I suspect it’s something fanciful that has been made up in modern times, came from one of those “healing stones and crystal therapy” peddlers, and has been continually repeated almost verbatim.

[CMD]

Thanks, Roger. Wolter claims that the Templars knew Cumberlandite as the "Venus Stone", a claim that was ludicrous from the start; since it's only found in Rhode Island, how would they have become familiar with it in the first place?  The Templars called it the "Venus stone", yet it only outcrops on a hill in Cumberland, RI :blink:  :unsure:  :dunno:  That claim is one of the more ridiculous and easily dismissed of Wolter's vast cargo of unsubstantiated imaginings. He also didn't realize it could be found in Newport as part of a boulder train, and, as a geologist, he could have ferreted out that information. No reason to think a boulder of Cumberlandite in the tower would be unusual for any reason.