An Article In Meteorite-Times Magazine
by Robert Verish

Slag Meteor-wrongs

Another "Sulfide slag" source found - it's FERRO-MANGANESE

UPDATED (2009-07-07): with new links and revised terminology

HERE is a link to my latest Bob Findings (July 2009) article about an Update on "Slag Meteor-wrongs"


All images taken by Bob Verish.

Perhaps it's just me, but there seems to be more mention of meteor-wrongs, lately. Perhaps there are more people actively searching for meteorites and, as a result, more meteor-wrongs are being found. But, I've also noticed that, when there is a mention of real meteorites (or fireballs) in the media, there always seems to be a rash of meteor-wrong findings that follows soon afterwards. Many times it's the mention of meteorites in the media that prompts the decendants of "meteorite finders" to fetch "grandpa's doorstop" out from the barn to "get it looked at". Although this scenario is actually how some meteorites have been brought to the attention of researchers, it is more often the case that the "family heirloom" is found to be nothing more than a disappointing meteor-wrong.

In the process of giving lectures to clubs and presenting displays of "real" meteorites (and even meteor-wrongs) at their meetings and shows, I am very often approached by people who have "found a meteorite". What this means is that I get to examine a lot of "meteor-wrongs". I get to see a lot of the typical hematite nodules and magnetite "irons", but there was this one type of meteor-wrong that I was consistanly being shown by a variety of people. It wasn't that great of a meteor-wrong because it wasn't attracted to a magnet, and it wasn't made of metal, but it was ALWAYS black, and heavy, and every person that showed their specimen to me were convinced that "it had to be made of metal". But, like I said, it wasn't metal. Granted, the interior had a metallic luster, but it wasn't "made of metal". When I would tell the finder that their "iron" was a man-made stone called "slag", they would always reply, "But it isn't glassy and it doesn't have any bubbles!"
And that's why it was necessary for me to coin the phrase, "Sulfide Slag".
But, although I was encountering this atypical meteor-wrong every more frequently, from a variety of people, I never could get a consistent story that would give me a clue as to a possible common origin. The consensus was that it had to be a by-product of a smeltering process, most likely in an iron furnace.

Click-to-ENLARGE Click-to-ENLARGE

Opening of Science of Rocks Show - - - My meteorite display at the Show

Then, last month, at one of those "Gem Shows" where I had my meteorites on display, a person handed me "a meteorite" that his son had found while walking to school. Well, I immediately recognized the hefty black rock as being, not only a meteor-wrong, but as being another specimen of that "sulfide slag". I said to this person, "This rock isn't attracted to a magnet, is it?" The person sheepishly admitted that, "No, it doesn't attract a magnet, and I read somewhere that most meteorites are magnetic, so I guess that doesn't bode well for this being a meteorite. Does it?" I didn't answer his rhetorical question, but instead asked another question, " Was this found near some railroad tracks?"
My question seemed to surprise him, and he answered, "Yes! How did you know that?"
I then proceeded to tell him my story about "sulfide slag" and my search for its (presumed) common source.

Click-to-ENLARGE Click-to-ENLARGE

As-found sulfide slag specimens - - - and after cleaning away the coating of clay and MnO2 powder.

All of this got me to wondering:

1) Just how common is this type of sulfide-rich slag?
and, since I knew that slag is used as ballast on the track-beds for railways,
2) Just how far would I have to walk along a railway track-bed before I would find my own piece of "sulfide slag"?

Since most of the railway track-beds that I was familiar with had used slag for track-ballast, I just picked a section of track that was near to my home, but was part of the main line that went up-state. I chose a 2 mile section that is used by passenger trains. But, as soon as I started walking, I discovered that the ballast used was mostly composed of natural rock. It seemed that for every 1/10th of a mile only one truckload of slag had been dumped and mixed into the track-ballast. Much less slag was being utilized than I had expected. And nearly all of that slag was of the light-colored, vesicular variety.
After walking a few tenths of a mile, finally a small piece of "sulfilde slag" was recovered. And when one piece was found, sometimes there would be a second or third fragment, as well, but never anymore than a few pieces at a time. Eventually, after walking less than 1.5 miles, I had already recovered 25 pieces of sulfide-rich, black powder-covered rock. One of the 25 pieces actually contained some iron metal, and was a meteor-wrong that closely imitated a stony-iron. The other 24 pieces were all the same, having a brassy, but granular to crystaline interior, somewhat akin to massive arsenopyrite. Cut surfaces would quickly tarnish in a matter of days if left in an outdoor environment. The exterior of each piece was a rind of decomposed sulfides forming a black powdery crust, much akin to manganese dioxide.


Tarnish developes on unprotected cut surface (right-side, left-side was protected) after just a couple weeks of exposure outdoors. The similarity of this man-made mineral to naturally occuring arsenopyrite is more than just a coincidence. [See in the "References: ", below, for the Slag piles contamination report.]

It didn't take too much detective work to track down the source of the slag used by the railway in their track-ballast. Nearly all of this slag comes from two huge slag heaps in Fontana (California) and was purposely dumped there by the Kaiser Steel Co.
[See the "References: ", below, for the Fontana Steel Mill.]


The black, sulfide-rich rock, which is here termed, "sulfide slag" [but a better term would be "ferro-manganese"], originated from a slag-heap at the former Kaiser Steel Mill in Fontana, California. This particular kind of slag is not produced (here in this country) in "steel furnaces", but was formed in the older "iron blast furnaces".


Bob's Findings - article titled, Update on "Slag Meteor-wrongs", in - July 2009.

Ferro manganese slag:

Import/Export - File for the International Uniform Chemical Information Database.
The ferromanganese slag is a lumpy, odor-free material with a green/brown coloured surface which can turn brown/black during storage:
** The analysis of the slag will vary based on the ore used in
** the production of HC FeMn, on the basicity used in the
** furnace operation and the slag adjustment materials used.
** Typical analysis:
** Mn 26-32%, present as MnO (33-42%)
** SiO2 approx. 24%
** Al2O3 max 12%, typ. 10%
** CaO approx. 18%
** MgO approx. 3%
** K2O max 2.5%
** P typ. 0.02%
** The slag is not a simple mixture of the listed elements/oxides as the elements are bound in a complex oxide/silicate structure. It would therefore be incorrect to report the elements/oxides as impurities.

Hot Rocks. Meteorite identification. Meteor-wrongs on the web ...

FERRO MANGANESE The interior "looks like" a natural sulfide mineral with a highly specular, metallic luster. But it is not a metal. It is actually a rock. It is composed of minerals termed, "Fe-Mn silicides"...

Ferrochrome lumps.

These are walnut-sized lumps of ferrochrome from a scrap metal shop in southern California.

Iron and Steel Slag: "Slag ain't Slag!"

File Format: PDF/Adobe Acrobat - View as HTML
Iron Slag = Blast Furnace Slag. Air-cooled. Granulated. Pelletized.
Steel Slag = Steel Furnace Slag. Bottom Boiler Slag ...

Why Control Sulfur Content?

How manganese controls sulfur content in steel processing.

Slag comes from the production of steel:

Accounting for 60% of the world's total output of crude steel, the Basic Oxygen Steelmaking (BOS) process is the dominant steelmaking technology.


The mineral, Pyrolusite, is the most important ore mineral of MANGANESE, forms dark gray to black coatings, crusts, columnar or granular masses, and rare crystals (polianite) that have one perfect cleavage. Pyrolusite results from alteration of MANGANITE and other manganese minerals.
About 95% of the world's annual production of manganese is used by the iron and steel industry to purify iron and to make alloys. Manganese is added to iron because it reduces iron oxide to form manganese oxide, which dissolves well in molten slag and is easily separated from the iron.


Definition and Much More from


Definition, Synonyms and Much More from


Definition, Synonyms and Much More from

Cast iron:

Definition, Synonyms and Much More from

Pig iron:

Definition, Synonyms and Much More from


is sometimes also referred to as specular pig iron, Spiegel iron, just Spiegel. Definition, Synonyms and Much More from

Specular pig iron:

[Definitions from] A fusible white cast iron containing a large amount of carbon (from three and a half to six per cent) and some manganese. When the manganese reaches twenty-five per cent and upwards it has a granular structure, and constitutes the alloy ferro manganese, largely used in the manufacture of Bessemer steel. Called also specular pig iron, spiegel, and spiegeleisen.
Webster's Revised Unabridged Dictionary, 1996, 1998 MICRA, Inc.

Blast Furnace Slag - Material Description:

User Guidelines for Waste and By-Product Materials Use in Pavement Construction.

Ferrochrome lumps.

These are walnut-sized lumps of ferrochrome from a scrap metal shop in southern California.


This is one of the most commonly misidentified 'meteorites' in Oregon.

U.S. GEOLOGICAL SURVEY Scientific Investigations Report 2004-5090.

Metallurgical Slag Particles in Accumulated Bed Sediments of Lake Roosevelt, Washington.

Fontana Steel Mill - slag piles

The East Slag Pile Landfill Area covers approximately 90 acres in the eastern half of the southern part of former steel mill. This area consists of a mound ... - 56k - Cached -

EnviroStor Database

The original Kaiser Steel Mill facility was located on 1200 acres in Fontana. The facility was a former integrated steel production plant that the Kaiser ...

Fontana Steel Mill - slag piles

One man's toxic waste is another man's meteor-wrong! Everything you didn't want to know about ...
East Slag Pile Landfill. Former Kaiser Steel Mill Site. Fontana, California. Project No. ..... Slag Pile itself consisted mostly of iron and steel slag, ... - -

[PDF] NegativeDeclaration

File Format: PDF/Adobe Acrobat - View as HTML
the former Kaiser Steel Mill site in Fontana, California. ... was used to store slag, a by-product of iron and steel production, from the ...

Source for Ni (nickel) in slag.

[meteorite-list] EBAY Slag for sale.

My previous articles can be found *HERE*

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