FMF - Friends of Minerals Forum, discussion and message board

[Jared3339]

I have seen many polished minerals recently from new people asking for identification. And I see these polished minerals in very large numbers all around. They are very common. However when i look at the professional collections on this forum I see none of these polished samples. Is this because the actual minerals of which these polished samples are not rare or of any real value to a collection or is it because the polishing of minerals is frowned upon on this forum and in mineralogy. The reason I ask this question is because I have a very large collection of these minerals and I am wondering if I should keep them or get rid of them. Any advice helps. Thanks.

[Jared3339]

I just wanted to say that a polished mineral, in my opinion is a mineral that had been put through a rock tumbler and smoothed out with a polish applied to the outer surface.

[prcantos]

This is a good question.

[Jordi Fabre]

[Pete Richards]

To add my two cents worth:

Our focus is on naturally occurring minerals, and on their properties that allow them to be identified. Many unaltered mineral specimens are also outside our interest, if they do not show enough properties for us to know or be able to reasonably guess what they are. In general, we would not keep them.

When a mineral is polished, many of its inherent properties are lost. These include crystal shape, luster, and surface features of crystals such as striations. The realities of the inexpensive polished stone market are that most polished stones are common minerals (if indeed they are not man-made), especially varieties of quartz, and are of very little interest as mineral specimens.

Factors that make minerals valuable and of interest to us include rarity, quality of crystal form, transparency, freedom from external and internal damage, and coming from a known locality for which the complete mineralogy and underlying geology are known. Additionally, some people collect minerals from certain geographic areas (e.g. Ohio minerals), minerals with particular chemistry (e.g. phosphates), or minerals with special geometric properties (e.g. twins).

Perhaps this will help you to understand why we are not interested in collections of pretty objects about which virtually nothing is known.

[Jared3339]

Thanks for the responses guys. I will be keeping them, and thanks for answering my question.

[Riccardo Modanesi]

Hi to everybody!
We can discuss all the time whether a cut gemstone or a tumbled one is a natural or artifact material. As a gemologist I can say natural polished and cut gemstones of mineral origin (therefore excluding ivory, coral, pearls etc.) ARE minerals. Even synthetic and treated gemstones are to be considered minerals as well. From the forming conditions of a synthetic gemstone we can understand so much about its natural formation environment (depth, temperature, geological environment etc.). However physical non-destructive analyses are readily available, like specific weight, refraction index/indexes, absorption spectrum (a good spectroscope is available in mineral shows at a very cheap price, here I can't tell you the amount but, believe me, it's affordable for everybody), inclusions (even a 10x loupe is very good and nowadays small travel microscope are available, and very cheap), etc.
Moreover: there are some forums about gemstones, I am enrolled in one whose name is "Gemology On Line". I knew about it right here in this forum.
I hope I was useful and didn't say anything forbidden. Greetings from Italy by Riccardo.

[Pete Modreski]

Let me try to add my own few comments to this--Jared, and all.

There is certainly nothing "prohibited" from being discussed here. (Well, maybe a few things; as you may have read, we have agreed that we won't include questions of value--i.e., "how much is this specimen worth", because we don't want it to turn into a commercial exchange bulletin board.) So, now and then, it's not inappropriate for someone to post something about a polished specimen; but as Pete Richards has pointed out, our main focus is minerals--as in (normally) crystallized mineral specimens--and there are other online places, elsewhere, designed specifically for those interested in gemstones, or for general "rockhounding" and lapidary (stone polishing) issues.

This brings us to the real focus of this group--and was first established as, and intended to be, a forum where mineral collectors could discuss, show pictures of, and ask questions or share informatioin about, mineral specimens--with the intention of appealing to a group who are already "established" mineral collectors, and know a reasonable amount about minerals, and enjoy viewing and discussing them. Of course, there is no requirement of any particular level of knowledge to join the group--really!--beginners are as welcome as any longtime experienced collector. But, what I'm trying to say, is that it wasn't intended as the place for someone who really doesn't consider themself to be a "mineral collector", to post pictures & questions of "I found this odd looking rock, what is it?", or "what are these pebbles that I got at the garage sale?". Now--here's the key thing--we really don't mind people, once in a while, happening on to this Forum and posting questions like these; we are always happy to try to answer them and inform people about what minerals & rocks are, really! Our "problem" has been that, of late, there have been such a large number of those kinds of questions posted to this Forum, that they are almost crowding out and outnumbering and overwhelming, the kinds of discussions that the Forum was intended to foster!

We are concerned that, if everyone on it sees that "half or more of the questions posted" are from non-collectors about "what is this funny/pretty stone" that I found/bought/was given, the "real" mineral collectors and enthusiasts will stop reading the forum and posting their own discussions, and it will encourage (as people see what's on here) more and more of the "beginner rockhound" (or not really even a rockhound at all) kind of questions.

Now, I am writing all this, partly in the hope that newcomers (like yourself, Jared) will see this and read it and have a better understanding of why we aren't more welcoming of these kinds of posts. There obviously IS an interest and a demand for a forum like this to get "general purpose rockhound and stone identification" questions answered--it's just that this wasn't the intended purpose of this Forum! I'm trying to say all this without sounding "snooty" about it, and, my apology if it does sound that way. And I'm also writing this in hopes--though we have discussed this many times before--it will still inspire some of our Forum members to suggest new and better ways that we can communicate, from the first time someone new looks at the home page of the Forum--that this is a site for, still groping for words here, "real collectors of mineral specimens", not a "rockhounds and beginners Q&A site".

P.S., back to you, Jared, if you're still reading--for the record, I think quite a few (4, at least) of the polished stones you show, are dyed stones of the sort that are (unfortunately) very common at rock shops & gift shops; for sure, the magenta one, the two blue ones (deep blue and pale blue), and perhaps the orangish-looking one too. One stone is definitely Tiger Eye. We really do like to be helpful, honest, and most of us really do enjoy helping to teach "beginners" more about rocks, minerals, and mineralogy.

Best wishes to you and to everyone,
Pete (Modreski)

[vic rzonca]

"We really do like to be helpful, honest, and most of us really do enjoy helping to teach "beginners" more about rocks, minerals, and mineralogy." Peter Modreski

Right on Peter. To that end Jared, I'd like to suggest, because you've come to us with your collection of polished stones, that you get the Audubon Society Field Guide to Rocks and Minerals, which has a gem stone section that shows polished and cut examples of some minerals. It will also introduce you to minerals, mineral ID, location info, chemistry of minerals, crystallography and a depth of mineral musing. But it's just a start. I'm pretty sure a lot of us on the forum started out finding fascination in a rock on the ground. I know I did. Stay interested. Good luck and I see you are from my home state, feel free to PM me, maybe a field trip or swap. Also consider joining a mineral club, if for no other reason you might get to meet codgers like this guy, older than dirt. Or Peter.

[Dale Hallmark]

I am guilty of posting stuff that frustrates the expert users here but it is an attempt to learn and share. I assume others do too.

Frustration...that is what I feel when someone asks to identify a polished thingy.

Everything that is used to identify a mineral (almost) is gone, destroyed. Is it glass? Is it plastic? Is it a man made mineral? Is it a natural mineral? Certainly not questions that can be answered from a picture or a scan.

About all that is left after polishing is color...the least reliable (almost totally worthless by itself) characteristic.

What I like are natural minerals and rocks (not crystals per se) that have a LONG history of usage by man for practical, religious or ornamental purposes but not specifically jewelry. Don't get me wrong jewelry is fine but not something I am interested in as a collector.

With likes like mine I don't fit too well here but it is a great place to learn! Sometime I don't share my acquisitions here because they don't fit well but I have a good time reading about the specimens of others.

Dale

[Jared3339]

Thanks a ton everybody for all the information. I am fairly new to this site and I can understand what the admins have to put up with. And just for the record, my father was a huge collector. Or should I say rockhound. But my family split a little while ago and I was left with his huge mineral collection. That's how I got into this. However with juggling school I haven't had the time to truly understand or research more about the subject. But it has always fascinated me.

Thanks for all the replies everyone

P.S. my non-polished collection vastly outnumbers my polished collection