Jewelry, Gems, & Minerals/What's this


Strange stone
Strange stone  
QUESTION: I got this stone from a friend,I was wondering what is this,it looks like a human heart😃could. it be  meteor?

ANSWER: Hi Amanda,
Doing interpretations from pictures alone is always a little tricky. However, your stone looks a lot like a chert nodule. Chert is a type of quartz (SiO2) that can precipitate out of water and replace other substances, such as wood, hence creating petrified wood. It can also replace other things, like fossil fragments. There are small planktonic animals called diatoms that make their tiny shells out of chert. When these microorganisms die, their shell remnants can make large chert layers on the bottoms of oceans and seas. If they stay loose and uncompacted we can mine these deposits as "diatomaceous earth", used as a natural, organic pesticide and as filtration material. However, these diatoms can also compact and become glued together, making chert beds or chert nodules which are solid rock.
From the mottled texture of your particular specimen it looks like that it might contain small fossils. But I am unsure because I can not see enough details. The spidery looking veins may have been cracks in a solidifying chert rock that were eventually filled with chert itself. This is the best explanation I can currently give you.

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Side one
Side one  
QUESTION: I'd really appreciate  of what you have helped me to get a new  opintion of this  stone,here is another picture from the side  viewing of it to get a whole image

Hi Amanda,
Thank you for the picture with greater detail. It looks a lot like some fossilized remains. However, I am not a fossil expert. (My background is in "Mineralogy and Applied Geology") Do you live close to a university? I would take your specimen and show it to someone in the Earthscience / Geology department with a background in "Paleontology". I am saying this because there might be a chance that these spidery webbing on the rock may be soft tissue fossilization, which is extremely rare. I maybe wrong and a chat with an expert in fossils would clarify this. But just per chance it is soft tissue fossilization you would indeed have a "find in a million". They probably may want to know where it was exactly that you found this specimen. Chances are that there might be more.
I still think that the mineral in your specimen is predominantly chert, but this is all I can tell you.
If you do show this to an expert at a local university, would you be so kind and let me know what he/she said? I would be very interested.
Good Luck  

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Uwe Richard Kackstaetter, Ph.D. (Dr.K)


I can answer questions concerning minerals, mineralogy, gems, metals, and anything that has to do with geology. However, I am NOT a jeweler. Questions about values, settings, gem stone cuts and appraisals are best directed to other experts on this site. I can however aide in the identification of unknown mineral materials. As a public service and part as training for new geoscientists, our university department provides FREE mineral identification for individuals. Please contact me for details or go to for details..


I am a professor of applied geology and mineralogy with many hours of field experience. Furthermore, I enjoy recreational gold prospecting and mineral collecting. As a professor I am engaged in research concerning minerals and their occurrence.

Member of the GPAA (Gold Prospectors Association of America) as well as the Association of Environmental Geochemists. Member of the GSA (Geologic Society of America) Member of the AIPG (American Institute of Professional Geologists)

Here is a small sampling: Mineral-rock handbook: Rapid-easy mineral-rock determination : written for anyone interested in minerals and rocks - Proctor, Peterson, and Kackstaetter;Macmillan Pub. Co. (New York and Toronto and New York) Physical Geology Laboratory e-Manual [CD-ROM], Kackstaetter, Earth Science Education LLC Colorado Front Range Self-guided Geology Field Trips, Kackstaetter,

Ph.D. in Applied Geology and Mineralogy. I am actively teaching courses in mineralogy and a variety of field courses with mineral collecting opportunities. Background in precious metal exploration.

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