22 replies to this topic

[unfindable]

Hello everyone, today by accident i stumbled on an unusual rock in the sand along the road during constructions there. They dug 2 meters down into yellow sand and dumped it along the side of the road. And in that sand i found this rock. It is very heavy and had a crust which sadly crumbled off but i got all the pieces. It is grey on the outside and pitch black on the inside and has a dimpled texture and weighs a whopping 2815 grams and measures 22 x 14 x 4 cm. I have not jet done a magnet test because i want to preserve the magnetic orientation. Could this be a meteorite?

Attached Thumbnails

• 
• 
• 
• 
• 

[John the Space Traveler]

My quick observations based on limited information makes me think it is not a meteorite.

Most meteorites (from my experience anyway) tend to be more rounded than flat.  Not spherical, mind you, just roughly rounded or oblong.  Your sample is a flat slab, which makes me think it is a piece broken off of a mostly flat terrestrial rock layer.

 

It reminds me of  a rock type called chert (or flint), and although it is hard to see in your photos, it might show conchoidal fracturing where pieces of it are broken, which is common to chert.  Chert is a fairly common rock, and here in my part of California it is dark gray to black.  It can be lighter in color however.

It's extremely hard to classify rocks based on photos, so nothing definite can be said here.  Any ideas offered on my part of at best informed guesses, and I would encourage you to send a small sample to a scientific lab specializing in meteorites, but first ask them if they are interested (UCLA does not accept unsolicited materials).  You can also email the geology and/or astronomy department of your local college and ask if they would like to see it.

 

I would do the magnet test as you will not reset any potential magnetic properties.  Meteorites, even the ones that are mostly stone, still have high iron content and will attract a magnet far more strongly than a common terrestrial rock with low iron content.  The magnet may not stick to it, but it will have a definite attraction.

 

Useful Links

• US Geological Survey:  I think I found a meteorite. How can I tell for sure?
• UCLA Meteorite Lab FAQ: https://meteorites.ucla.edu/faq/
• Lunar & Planetary Lab (UA): https://www.lpl.ariz...each/meteorites

Good luck!

Edited by John the Space Traveler, 25 January 2024 - 02:52 PM.

[Sincos]

If you truly believe you are a hammer , all you will see are nails .  

[unfindable]

My quick observations based on limited information makes me think it is not a meteorite.

Most meteorites (from my experience anyway) tend to be more rounded than flat.  Not spherical, mind you, just roughly rounded or oblong.  Your sample is a flat slab, which makes me think it is a piece broken off of a mostly flat terrestrial rock layer.

 

It reminds me of  a rock type called chert (or flint), and although it is hard to see in your photos, it might show conchoidal fracturing where pieces of it are broken, which is common to chert.  Chert is a fairly common rock, and here in my part of California it is dark gray to black.  It can be lighter in color however.

It's extremely hard to classify rocks based on photos, so nothing definite can be said here.  Any ideas offered on my part of at best informed guesses, and I would encourage you to send a small sample to a scientific lab specializing in meteorites, but first ask them if they are interested (UCLA does not accept unsolicited materials).  You can also email the geology and/or astronomy department of your local college and ask if they would like to see it.

 

I would do the magnet test as you will not reset any potential magnetic properties.  Meteorites, even the ones that are mostly stone, still have high iron content and will attract a magnet far more strongly than a common terrestrial rock with low iron content.  The magnet may not stick to it, but it will have a definite attraction.

 

Useful Links

• US Geological Survey:  I think I found a meteorite. How can I tell for sure?
• UCLA Meteorite Lab FAQ: https://meteorites.ucla.edu/faq/
• Lunar & Planetary Lab (UA): https://www.lpl.ariz...each/meteorites

Good luck!

just wanted to post it quickly, thats why the photoś with flash, but low resulution. so indeed hard to tell.

[unfindable]

If you truly believe you are a hammer , all you will see are nails .  

Yes if this i truly a nail i would love to be an hammer. There more going on with this rock that you can see on the photoś .

[ButterFly]

... weighs a whopping 2815 grams and measures 22 x 14 x 4 cm.

At a density of about 2.2 grams per cubic centimeter, it's as dense as graphite.  Chondrites are on the order of 3-4 g/cm3 and stony ones on the order of 7-8 g/cm3.  Don't waste the postage on this one.

[John the Space Traveler]

At a density of about 2.2 grams per cubic centimeter, it's as dense as graphite.  Chondrites are on the order of 3-4 g/cm3 and stony ones on the order of 7-8 g/cm3.  Don't waste the postage on this one.

Clever observation, ButterFly.  Math doesn't lie.  That calculation is in line with UCLA's meteorite page in the link which says "Iron meteorites have very high densities (7.4 to 7.9 times that of water) and weigh about three times as much as Earth rocks of similar size; most chondrites [stony meteorites] weigh about one and a half times as much as comparably-sized earth rocks."

Unfindable, you can look up the density values for water and compare.  If want to compare its density to the most common Earth rocks, that would be -- in a very general sense -- granite (the primary component of continental crust) and basalt (the primary component of the sea floor).

Edited by John the Space Traveler, 25 January 2024 - 04:18 PM.

[unfindable]

At a density of about 2.2 grams per cubic centimeter, it's as dense as graphite.  Chondrites are on the order of 3-4 g/cm3 and stony ones on the order of 7-8 g/cm3.  Don't waste the postage on this one.

your wright about 2,2 cubic cm, but if it was a meteorite it would be a carbonaceous meteorite and those have a lower density. c ones have 2,8 or 2,9. but i think the way forward is to cut of a piece and se what is hiding inside.

[John the Space Traveler]

your wright about 2,2 cubic cm, but if it was a meteorite it would be a carbonaceous meteorite and those have a lower density. c ones have 2,8 or 2,9. but i think the way forward is to cut of a piece and se what is hiding inside.

It would be helpful to share a clear video with the group of you doing a magnet test.  That's going to be a powerful indicator regardless of density.

Edited by John the Space Traveler, 25 January 2024 - 05:39 PM.

[unfindable]

It would be helpful to share a clear video with the group of you doing a magnet test.  That's going to be a powerful indicator regardless of density.

it doesn´t atract a magnet, so probably limestone or chert.

[lee14]

Magnetic attraction, lack thereof, or density are not powerful indicators of anything. There is a full spectrum of values where both terrestrial and meteoritic material can fall. When the visual appearance is reminiscent of meteoritic origin, diagnostic tests might be indicated. This is not the case here. In most of the other terrestrial rocks we've recently seen here, they either lack any resemblance to meteorites or exhibit characteristics which confirm terrestrial origin. Application of Occam's Razor and proper use of the scientific method would seem to be what is needed here.

 

Lee

[unfindable]

Magnetic attraction, lack thereof, or density are not powerful indicators of anything. There is a full spectrum of values where both terrestrial and meteoritic material can fall. When the visual appearance is reminiscent of meteoritic origin, diagnostic tests might be indicated. This is not the case here. In most of the other terrestrial rocks we've recently seen here, they either lack any resemblance to meteorites or exhibit characteristics which confirm terrestrial origin. Application of Occam's Razor and proper use of the scientific method would seem to be what is needed here.

 

Lee

thanks, should i make new better fotoś in daylight or is that not necessary? Found this round thing on it. and this is the texure.

Attached Thumbnails

• 
• 

[lee14]

It's extremely hard to classify rocks based on photos, so nothing definite can be said here.

Your images are perfectly fine. The relevance of John's statement cannot be understated though, and is quite correct. Conversely, while it is extremely difficult to identify what type of terrestrial material it is, it's relatively straightforward to rule out the likelihood that the specimen in question is a meteorite. As far as appearance goes, none of the characteristics, neither shape, color, nor texture are indicative of meteoritic origin. In fact, a light exterior and dark interior are precisely the opposite of what would be expected. Regarding actual composition or internal structure, no data is offered.

 

Lee

Edited by lee14, 26 January 2024 - 06:37 AM.

[Glassthrower]

[John the Space Traveler]

Magnetic attraction, lack thereof, or density are not powerful indicators of anything. There is a full spectrum of values where both terrestrial and meteoritic material can fall. When the visual appearance is reminiscent of meteoritic origin, diagnostic tests might be indicated.

This statement is not correct.  Density and magnetism are both diagnostic tests.  While it is technically true that there is a "full spectrum of values where both terrestrial and meteoritic material can fall", in nature that is generally NOT the case.  Meteorites have a general trend of characteristics that fall in a specific and narrow range of values and traits, and we use those trends to sort the wheat from the weeds.

 

The majority of meteorites have specific intrinsic (invisible) and extrinsic (visible) qualities that can be looked for in the field.  That way geologists don't waste their time bringing back truck loads of "meteor-wrongs".  Attraction to magnets is a common, basic characteristic of most meteorites.  That's why NASA, the USGS, academia, meteorite dealers, textbooks and field guides all encourage testing for it in their published materials. 

 

By itself magnetism doesn't indicate a positive meteorite ID.  Certain terrestrial rocks like magnetite have similar magnetic properties, and that's why we don't focus on a single characteristic.  But magnetism can be a strong indicator when used in conjunction with other known meteorite qualities. Lunar and Martian meteorites generally lack this magnetic characteristic, but they have a number of other indicators that can help ID them in the field or at home.  So while the magnet test isn't useful with them, they are also very rare, only making up 1% of meteorite finds at best.  Yet we do use magnetism to help ID the other 99%.  So while there are some exceptions to using magnetism, generally it is a great tool for the majority of meteorite candidates.

 

As a geologist, let me explain how we identify potential meteorites and other rocks quickly in the field.  More precise, specific typing can be done later in the lab, but general typing is easy to do based on the following characteristics.  Following this method keeps us from bringing back truck loads of mostly useless samples when we can more wisely bring back a few buckets of useful ones.

 

Rocks, whether from Earth or space, are typically made up of different minerals collected together (exceptions exist).  For example, granite rocks are primarily made of the intertwined mineral crystals of quartz, potassium feldspar, and sodium feldspar.  In the field, a quick test can be done to ID the rock using the properties that those minerals have.  We essentially follow a flow chart of characteristics to narrow down the possibilities.  Anything falling outside of these basic characteristics may or may not get special attention.

 

IDENTIFYING CHARACTERISTICS

• Hardness (specifically Moh's Hardness Scale).
   
• Color
   
• Magnet test.  Indicates if the sample has ferrous properties (iron).
   
• Streak:  Colored residue left behind by scratching a mineral across an abrasive surface like a piece of unglazed porcelain.  Meteorites don't leave a streak.
   
• Luster: The light reflection properties of a mineral that indicate if it is metallic or nonmetallic.
   
• Cleavage: The tendency for minerals to break along flat planar surfaces.  That's the conchoidal fracturing I was talking about in my first post.
   
• Acid test (aka "the fizz quiz"): If a weak acid is put on it, does it "fizz"?  If so, it probably contains calcium carbonate, which hints that it was likely part of a marine deposit in the past (i.e. sea life was present).  Marble and limestone famously do this.

While analysis back in the lab is the most definitive method to ID a sample, these basic tests root out rocks that are not desired by scientists in their field work.

Additional things we look for in suspected meteorites that are not found in terrestrial rocks include a fusion crust, regmaglypts (thumb prints), weather-resistance (due to density), and chondrule presence.

Edited by John the Space Traveler, 27 January 2024 - 05:13 AM.

[lee14]

The identifying characteristics you've identified are well suited for an initial determination of the composition of native rocks and minerals. Absolutely.

However, ruling out the possibility of meteoritic origin is not an equivalent process. Quite often this can be done merely from an image, while identification of the actual material actually is, remains another matter.

 

Rocks that seem to exhibit characteristics commonly seen on meteorites is something else and necessitates laboratory analysis. Features that might appear as fusion crust, regmaglypts, or chondrules can be seen on terrestrial material, but can be concretions, differential weathering, or desert varnish. To the inexperienced eye, certain conglomerates might be seen to indicate the presence of chondrules. Conversely, genuine meteorites may lack those same characteristics. Genuine fusion crusts are most often seen in fresh falls, many fresh or older specimens lack regmaglypts. An entire class of stony  meteorites are devoid of chondrules, another group lacks sufficient iron to react to the magnet test.

 

The OP, an enthusiastic collector, has posted an image and asked whether or not it's a meteorite. The answer is as simple and complete as Glassthrower's response above.

 

Lee

[unfindable]

This statement is not correct.  Density and magnetism are both diagnostic tests.  While it is technically true that there is a "full spectrum of values where both terrestrial and meteoritic material can fall", in nature that is generally NOT the case.  Meteorites have a general trend of characteristics that fall in a specific and narrow range of values and traits, and we use those trends to sort the wheat from the weeds.

 

The majority of meteorites have specific intrinsic (invisible) and extrinsic (visible) qualities that can be looked for in the field.  That way geologists don't waste their time bringing back truck loads of "meteor-wrongs".  Attraction to magnets is a common, basic characteristic of most meteorites.  That's why NASA, the USGS, academia, meteorite dealers, textbooks and field guides all encourage testing for it in their published materials. 

 

By itself magnetism doesn't indicate a positive meteorite ID.  Certain terrestrial rocks like magnetite have similar magnetic properties, and that's why we don't focus on a single characteristic.  But magnetism can be a strong indicator when used in conjunction with other known meteorite qualities. Lunar and Martian meteorites generally lack this magnetic characteristic, but they have a number of other indicators that can help ID them in the field or at home.  So while the magnet test isn't useful with them, they are also very rare, only making up 1% of meteorite finds at best.  Yet we do use magnetism to help ID the other 99%.  So while there are some exceptions to using magnetism, generally it is a great tool for the majority of meteorite candidates.

 

As a geologist, let me explain how we identify potential meteorites and other rocks quickly in the field.  More precise, specific typing can be done later in the lab, but general typing is easy to do based on the following characteristics.  Following this method keeps us from bringing back truck loads of mostly useless samples when we can more wisely bring back a few buckets of useful ones.

 

Rocks, whether from Earth or space, are typically made up of different minerals collected together (exceptions exist).  For example, granite rocks are primarily made of the intertwined mineral crystals of quartz, potassium feldspar, and sodium feldspar.  In the field, a quick test can be done to ID the rock using the properties that those minerals have.  We essentially follow a flow chart of characteristics to narrow down the possibilities.  Anything falling outside of these basic characteristics may or may not get special attention.

 

IDENTIFYING CHARACTERISTICS

• Hardness (specifically Moh's Hardness Scale).
   
• Color
   
• Magnet test.  Indicates if the sample has ferrous properties (iron).
   
• Streak:  Colored residue left behind by scratching a mineral across an abrasive surface like a piece of unglazed porcelain.  Meteorites don't leave a streak.
   
• Luster: The light reflection properties of a mineral that indicate if it is metallic or nonmetallic.
   
• Cleavage: The tendency for minerals to break along flat planar surfaces.  That's the conchoidal fracturing I was talking about in my first post.
   
• Acid test (aka "the fizz quiz"): If a weak acid is put on it, does it "fizz"?  If so, it probably contains calcium carbonate, which hints that it was likely part of a marine deposit in the past (i.e. sea life was present).  Marble and limestone famously do this.

While analysis back in the lab is the most definitive method to ID a sample, these basic tests root out rocks that are not desired by scientists in their field work.

Additional things we look for in suspected meteorites that are not found in terrestrial rocks include a fusion crust, regmaglypts (thumb prints), weather-resistance (due to density), and chondrule presence.

Thanks wow alot of knowhow. have done an acid test and it reacted strongly so it is limestone with a weathering rind. Also hit it with a hammer and it made a sound like glass or metal so again not good. Thanks everyone for all the input. And i have some news about the other topic. th possible meteorite artefact. please see that and hopefully someone knows more.
 

[John the Space Traveler]

it doesn´t atract a magnet, so probably limestone or chert.

Unfindable, I think you are on a good track here.  If you have any doubts, or are confused by any contradictory opinions here, I suggest going to the web sites of people that do this for a living; NASA and the US Geological Survey.  After all, they are the ones collecting not just meteorites, but pristine samples from the Moon, comets and asteroids.  Their advice is the most sound.  I've included those links below.  You'll have to copy and paste the links into your browser.

 

• NASA:
• https://www.jpl.nasa...ite-page-1-of-2
• US Geological Survey:
• https://www.usgs.gov...can-i-tell-sure

 

Other web sites respected by scientists in the meteorite study field:

• https://geology.com/...ification.shtml
• https://sites.wustl....ems/what_to_do/
• http://meteorite.unm...w-id-meteorite/
• http://meteorite-ide...com/streak.html
• https://sites.wustl....est-check-list/
• https://xkcd.com/1723/

[unfindable]

 

Unfindable, I think you are on a good track here.  If you have any doubts, or are confused by any contradictory opinions here, I suggest going to the web sites of people that do this for a living; NASA and the US Geological Survey.  After all, they are the ones collecting not just meteorites, but pristine samples from the Moon, comets and asteroids.  Their advice is the most sound.  I've included those links below.  You'll have to copy and paste the links into your browser.

 

• NASA:
• https://www.jpl.nasa...ite-page-1-of-2
• US Geological Survey:
• https://www.usgs.gov...can-i-tell-sure

 

Other web sites respected by scientists in the meteorite study field:

• https://geology.com/...ification.shtml
• https://sites.wustl....ems/what_to_do/
• http://meteorite.unm...w-id-meteorite/
• http://meteorite-ide...com/streak.html
• https://sites.wustl....est-check-list/
• https://xkcd.com/1723/

 

thanks

[John the Space Traveler]

Thanks wow alot of knowhow. have done an acid test and it reacted strongly so it is limestone with a weathering rind. Also hit it with a hammer and it made a sound like glass or metal so again not good. Thanks everyone for all the input. And i have some news about the other topic. th possible meteorite artefact. please see that and hopefully someone knows more.
 

Good job!  You answered the question of is it or isn't it from space.  Now while you might be disappointed that it isn't a meteorite, you still have an interesting rock if it really is limestone or its metamorphosed cousin, marble (the acid test strongly implies it is, as does that ceramic sound you heard).  As a matter of fact, if you were an astronaut on Mars and found limestone, that would be a far greater discovery than pretty much any other rock on the planet!  Why?  Limestone is usually the product of living things.  So an astronaut on Mars that found limestone may have answered the question of whether life has existed elsewhere in the Universe.

 

A few years back I was doing paleontological studies on the Colorado Plateau in Northern Arizona.  We were studying marine fossils found in limestone layers.  Here is the really neat thing:  Those fossils and the surrounding limestone were laid down in warm, shallow seas ~300 million years ago when Arizona was about 10 degrees north of the equator, or about the same latitude as Costa Rica today.  Over millions of years those rocks slowly drifted 25 degrees north (1740 miles/2800 km), and were uplifted from sea level to to an altitude of 1.2 miles/2 kilometers.  Now, how did what would be an awesome beach vacation destination today move thousands of miles north and become part of a mountain ski area?

Plate tectonics!  This is proof that continents are drifting around the Earth, that mountains are made by powerful uplifting forces, and that former warm seas and beaches can end up in the snowy mountains.  What a cool story that rock has to tell! 

So my suggestion to you is:

1. Carefully chip at the rock (safety goggles on) and see if any fossils are present.
    
2. Look up your local geology online or at the library and see how that rock got there, and what fossils are in it.  How old is it, and how did it get buried?

Do this and I'm sure you too may find that rock has an interesting story to tell.  Have fun!

Edited by John the Space Traveler, 28 January 2024 - 12:00 AM.

[unfindable]

Good job!  You answered the question of is it or isn't it from space.  Now while you might be disappointed that it isn't a meteorite, you still have an interesting rock if it really is limestone or its metamorphosed cousin, marble (the acid test strongly implies it is, as does that ceramic sound you heard).  As a matter of fact, if you were an astronaut on Mars and found limestone, that would be a far greater discovery than pretty much any other rock on the planet!  Why?  Limestone is usually the product of living things.  So an astronaut on Mars that found limestone may have answered the question of whether life has existed elsewhere in the Universe.

 

A few years back I was doing paleontological studies on the Colorado Plateau in Northern Arizona.  We were studying marine fossils found in limestone layers.  Here is the really neat thing:  Those fossils and the surrounding limestone were laid down in warm, shallow seas ~300 million years ago when Arizona was about 10 degrees north of the equator, or about the same latitude as Costa Rica today.  Over millions of years those rocks slowly drifted 25 degrees north (1740 miles/2800 km), and were uplifted from sea level to to an altitude of 1.2 miles/2 kilometers.  Now, how did what would be an awesome beach vacation destination today move thousands of miles north and become part of a mountain ski area?

Plate tectonics!  This is proof that continents are drifting around the Earth, that mountains are made by powerful uplifting forces, and that former warm seas and beaches can end up in the snowy mountains.  What a cool story that rock has to tell! 

So my suggestion to you is:

1. Carefully chip at the rock (safety goggles on) and see if any fossils are present.
    
2. Look up your local geology online or at the library and see how that rock got there, and what fossils are in it.  How old is it, and how did it get buried?

Do this and I'm sure you too may find that rock has an interesting story to tell.  Have fun!

Hello thanks for the info. what are your thoughts about my other post. the meteorite artefact/object.

[John the Space Traveler]

Hello thanks for the info. what are your thoughts about my other post. the meteorite artefact/object.

Maybe I accidentally overlooked it.  Was it on this page?  Do you have a link to it?

[unfindable]

Maybe I accidentally overlooked it.  Was it on this page?  Do you have a link to it?

this is the link: https://www.cloudyni...orite-artefact/