Preliminary: Rocks and Minerals

[Luo]

I spent the last two weeks of school in AP env. cleaning out the back closets, filled with geology stuff, and we have nearly 200 different rock samples, which is bound to help with ID, but I also noticed that the scratch test boxes included nails and pennies. Are these helpful?

You wouldn't be allowed to bring those materials with you to the event. However, you could use them to practice determining hardnesses because the event supervisor might provide those materials for you to use during the event.

[purplepeopleeater]

I spent the last two weeks of school in AP env. cleaning out the back closets, filled with geology stuff, and we have nearly 200 different rock samples, which is bound to help with ID, but I also noticed that the scratch test boxes included nails and pennies. Are these helpful?

But are they helpful??? uh YEAH. it ALWAYS helps to have the actual sample you can see and touch and "test"
lucky and nice find

[kjhsscioly]

I spent the last two weeks of school in AP env. cleaning out the back closets, filled with geology stuff, and we have nearly 200 different rock samples, which is bound to help with ID, but I also noticed that the scratch test boxes included nails and pennies. Are these helpful?

You wouldn't be allowed to bring those materials with you to the event. However, you could use them to practice determining hardnesses because the event supervisor might provide those materials for you to use during the event.

I actually was asking if the pennies or nails are used for scratch tests. Can they tell you any more than a glass plate?

[quizbowl]

I spent the last two weeks of school in AP env. cleaning out the back closets, filled with geology stuff, and we have nearly 200 different rock samples, which is bound to help with ID, but I also noticed that the scratch test boxes included nails and pennies. Are these helpful?

You wouldn't be allowed to bring those materials with you to the event. However, you could use them to practice determining hardnesses because the event supervisor might provide those materials for you to use during the event.

I actually was asking if the pennies or nails are used for scratch tests. Can they tell you any more than a glass plate?

For some, you do have fingernails.

[Luo]

I spent the last two weeks of school in AP env. cleaning out the back closets, filled with geology stuff, and we have nearly 200 different rock samples, which is bound to help with ID, but I also noticed that the scratch test boxes included nails and pennies. Are these helpful?

You wouldn't be allowed to bring those materials with you to the event. However, you could use them to practice determining hardnesses because the event supervisor might provide those materials for you to use during the event.

I actually was asking if the pennies or nails are used for scratch tests. Can they tell you any more than a glass plate?

Yep, you could definitely use pennies (hardness 3.2-3.5), nails (hardness 4-4.5), fingernails (hardness 2.2-2.5), and glass plates (hardness 7) to help measure the hardness of rock/mineral samples.

[Mimsie]

For Graphite I have a 'rub' test. I just rub it really hard and see if this residue comes off on your hand. If you've ever been horrible about writing (like me) you've gotten pencil graphite all over your hands(between the wrist and pinky) and it looks very much like that.

I don't see how people get pyrite/chalcopyrite messed up with gold. They look so radically different. It's kind of amusing. (Gold is much more... continuous? Constant? idk how to describe it xD)

Let's see... what other telltale signs do I know. Oh. Almandine is easy, it has a very distinct (IMO) pattern. Gypsum often looks almost like calcite but you can scratch gypsum very very easily and gypsum just looks... different, it's more of a parallelogram solid structure. Talc. Oh god. I misidentified talc once (Go ahead R&M veterans, laugh at me) and it costed me first place (I got 2nd). But yeah, you can definitely scratch talc and if you want to, try to break off a little (TINY) piece. if you can snap it that easily, it is for sure talc. Besides, it also feels silky (ish)

[gneissisnice]

For Graphite I have a 'rub' test. I just rub it really hard and see if this residue comes off on your hand. If you've ever been horrible about writing (like me) you've gotten pencil graphite all over your hands(between the wrist and pinky) and it looks very much like that.

I don't see how people get pyrite/chalcopyrite messed up with gold. They look so radically different. It's kind of amusing. (Gold is much more... continuous? Constant? idk how to describe it xD)

Let's see... what other telltale signs do I know. Oh. Almandine is easy, it has a very distinct (IMO) pattern. Gypsum often looks almost like calcite but you can scratch gypsum very very easily and gypsum just looks... different, it's more of a parallelogram solid structure. Talc. Oh god. I misidentified talc once (Go ahead R&M veterans, laugh at me) and it costed me first place (I got 2nd). But yeah, you can definitely scratch talc and if you want to, try to break off a little (TINY) piece. if you can snap it that easily, it is for sure talc. Besides, it also feels silky (ish)

Yeah, if you're doubtful about graphite, just draw on the paper with it, or rub it. You'll definitely see that it's graphite. Pyrite and chalcopyrite look nothing like gold, they're very easy to tell apart (chalcopyrite and bornite can be extremely tough to tell apart when their both tarnished or untarnished, but you can basically just assume that the tarnished one is bornite and the untarnished one is chalcopyrite}. Garnet has a very distinct crystal structure. While gypsum is very soft, calcite is only 1 unit harder (though you can scratch gypsum with a fingernail but not calcite). But I've noticed that gypsum often looks...frosty, for lack of a better word, and calcite has unique optical properties (double refraction) as well as fizzing in acid. And talc should feel greasy; that's the best term for it.

[Cheesy Pie]

Just curious, but will they ask questions on mineraloids, like opal?

[butter side up]

What exactly is a mineraloid, anyway?

[Cheesy Pie]

Almost a mineral but not quite. Can be considered a mineral or a nonmineral. Like opal. Its either poorly crystalline or amorphous.