ok my friend gave me this rock he found within a nother rock,it is shiny silver, and very heavy, it cuts glass
399999
I am not really sure b/c of insufficient information.\n\nWhen you said silvery I thought of the mineral galena but it is too soft to cut glass.\n\nThen I thought about Hematite. It has a hardness of about 6 to 6.5 which is definitely harder than glass (5.5). Hematite is also found in sedimentary rocks which would make sense with what you described.\n\nHematite is not really heavy (not like galena which contains lead) but it is heavier than most rocks/minerals.\n\nHowever, I have problems with not being able to break hematite w/ a sledgehammer. It looks like it would give at some point.\n\nTo see for yourself what some forms of hematite look like go to the links below. Hematite is interesting in that it takes on many different forms/habits.\n\n:)
36455
The common name of such a type of rock is obsidian.
784045
A STONE THAT FELL ONTOP OFA TREADMILL!!
603021
A Corundum Ruby cause it's #9 om the hardness scale of minerals right under diamonds #10.
631145
I have to admit im not too clued up on the geology of Maryland, however over here in the UK we have in the Mendip Hills something which resembles Obsidian but in fact its not. On a university field trip we went to an old smelt, where the guys used to smelt Limestone and the result was this black shiny stuff that looked identical to Obsidian. The stuff was strewn all over the place in big heaps. Confused the 'ell out of us students initially until we were told the what it actually was. I wish I could remember more about it but then again uni was a bit of a blur!
781357
honestly, more than likely very little. it is not known where exactly it was found, or you could not prove it. individual pieces are only valuable to an anthropologist or to the local archaeologist, but again, where it was found is just as important as the item itself\na 10 inch stone (i presume) projectile point is unlikely. it may not be broken at all, it could be a tool
585350
Woah I just answered this question. Weird. The 15 year gift is Crystal. As in, wine glasses, etc. For gemstones its Ruby.
411879
A.K.A the Sorcercer's stone. it excist but I can't determine it's location at this time. It turns metals to gold and makes the drinker immortal. I'll be the future owner so hands off!!
281360
its a rock...\n\npencils...
1096251
One easy quick & easy way to find out is the streak test. Rub the mineral in question across an unglazed porcelain tile. If the streak it makes is black then it is pyrite (fool's gold). If it is golden yellow then you have gold. You can find these tiles in your local home & garden shop or hardware store.\n\nAnother simple one is the hardness test. Gold has a hardness of 2.5 to 3 on Moh's Scale. Pyrite is 6 to 6.5. Glass has a hardness of about 5.5. According to Moh's scale you should be able to scratch glass w/ pyrite but not w/ gold. Pennies can also be used as their hardness is about 3.5.\n\nGold is found in several different forms or habits. It can be dendritic (vein-like) or massive as in nuggets. Upon examining pyrite more closely (perhaps w/ a 10x magnifier) you will see that while it resembles a gold nugget it is actually made up of many tiny little cubes.\n\nGold will not cleave whereas pyrite will. Cleavage is simply how a mineral breaks evenly due to weaknesses in its crystal structure. Pyrite has cubic cleavage so that when it is hammered it will come apart in perfect little cubes.
1044022
sounds like it might be an ammonite fossil.  Depending on the species, size and its condition it could be worth a lot.  I saw some selling at the Nature Company for a lot of money.  Contact local university esp if they have a museum. You want to ask for a Malacologist (expert on Mollusks) someone who is good at IDing this kind of thing.  Ammonites are Cephalopods, relatives of squid and octopus and are NOT snails-Gastropods.
605675
First of all most stones will scratch glass...A cubic zirconia sapphire and ruby and quite a few other stones are harder than glass...A diamond can be broke by just banging it into you car door accidentally and I have seen that happen...Unless you have some pretty special equipment or a lot of knowledge at what you are looking at your not going to ever be certain...Take it to a jeweler and have them look at it or even a pawn shop, usually they have a tester they can touch the stone with and know in a second if its real or not without having to get a real appraisal and they will probably do it for you for free
493713
See it through a magifying glass. it will look 'BIGGER'
1031720
Search for a stone like that on Ebay, and see what they go for.
259893
It cant be just any piece of glass, it has to be a prism. The light comes out in the form of a rainbow because the prism separates the light into it's visible colors.
1163228
...Junyong, you sure seem to have a habit of passing all your homework assignment onto us - hoping that we will do it all for you, so that you can simply copy and paste it directly into your worksheets ! \nYou MUST learn to do your homework by yourself, dear - because others will not be around to help you in your final examinations, and you will also be having no first-hand knowledge of what can be found where !\n'Science fiction' is a highly technical field, and the current market rates for even the shortest (but technically correct) piece are around US $ 500/- ! Nobody is going to bother write one for you - in return for the points they get !\n...I'll give you some tips, though : Geology is the science that deals with the history of the earth as recorded in rocks. So, you could write a tale about a rare piece of rock that a child accidentally finds in their garden - which has an unusual gleam. The child's parents think it must be a semi-precious stone - and take it to be evaluated by a jeweller. He tests it, looks shocked, and secretly phones up the Space Research people. They come, examine it, and look even more shocked : The secret is finally revealed - that it is NOT from our Earth at all - but a unique specimen that must have come from a meteor [speedily flying fragment of rock, which has broken off from some other planet !]. \n...Since they already have samples from the Moon and Mars, the scientists feel certain that this stone is NOT from either - as its constituents are different. \n...Then where is it from ? And how did it fall into the garden of this child's home ? Have any other such pieces been found, or reported ?    \n....The answer comes from the least expected source !....\n...I've given you the outline. Now, be a dear, write the story in your own words, and give it a surprising ENDING - to show how clever and imaginative you really are. \n[On purpose, I've not ended the story !]\n...Best of Luck, dear.
730514
Most rocks thought to be meteorites are not. There are what they call "meteorwrongs". I found a rock myself that's all metal and rather heavy. That's how I found this site. You could also take it to a museum. Someone there will know. Take a look at these pictures.\n.