Rocks & Minerals B/C

[ScottMaurer19]

Anyone else notice that crystalline limestone is not on the official list anymore

[Kyanite]

Anyone else notice that crystalline limestone is not on the official list anymore

I did see that, really need to take it out of my notes

[ScottMaurer19]

Anyone else notice that crystalline limestone is not on the official list anymore

I did see that, really need to take it out of my notes

I swear I saw it on a test this year and got it right but

EDIT: I guess we can't confuse dolostone and crystalline limestone now so that's an improvement

[Kyanite]

Anyone else notice that crystalline limestone is not on the official list anymore

I did see that, really need to take it out of my notes

I swear I saw it on a test this year and got it right but

EDIT: I guess we can't confuse dolostone and crystalline limestone now so that's an improvement

True, that was an annoying ID mix up.

[gvorwald]

Crystalline limestone was taken out because it really is not a scientific term used for limestone. Travertine is a crystalline limestone, and often skeletal or fossiliferous limestone is cemented with crystalline calcite.

Limestone is actually classified through two systems based on either Folk or Dunham. I prefer Dunham which is based on amount of mud vs grains: mudstone, wackestone, packstone, grainstone. This is beyond the rules for this year, but I thought I would offer an explanation about crystalline limestone.

Gary Vorwald
National Supervisor 2017-18
Rocks & Minerals C Division

[gvorwald]

Some good resources for Rocks and Minerals, both B and C, are posted on the National Science Olympiad website:
https://www.soinc.org/rocks-and-minerals-b

For Rocks, look up various tables and charts on the Internet for:

Rock Cycle
Igneous Rock Chart
Sedimentary Rock Chart
Metamorphic Rock Chart
Metamorphic Environments

Don't limit yourself to the NYS Earth Science Reference Tables. They were based on other published charts. Choose the charts that include many of the rocks on the 2018 Science OIympiad list, and the ones that work best for you.

Gary Vorwald
2018 National Supervisor
Rocks & Minerals C Division

[gvorwald]

Some time ago, there was a question about how to tell the difference between Bornite and Chalcopyrite. Both are very similar ores of copper, but with different chemical formulas. Both are Copper Iron Sulfides, but with different percentages or each of these elements.

Most "peacock ore" or "peacock copper" is chalcopyrite that has been treated with acid to enhance its iridescence. Both can be iridescent naturally due to exposure to air, although Bornite is usually shades of blue and purple. Unfortunately, most event supervisors may not be as knowledgeable about differentiating these two minerals. Both have similar density, luster, hardness, uneven fracture, etc.

If you have a freshly broken specimen, Chalcopyrite will be golden yellow, and Bornite coppery brown. However, I don't feel it fair to ask for identification of these two minerals without providing some information that can be used to distinguish them, such as the formula, or information about the unoxidized color, etc.

Gary Vorwald
2018 National Supervisor
Rocks & Minerals C

[ScottMaurer19]

Some time ago, there was a question about how to tell the difference between Bornite and Chalcopyrite. Both are very similar ores of copper, but with different chemical formulas. Both are Copper Iron Sulfides, but with different percentages or each of these elements.

Most "peacock ore" or "peacock copper" is chalcopyrite that has been treated with acid to enhance its iridescence. Both can be iridescent naturally due to exposure to air, although Bornite is usually shades of blue and purple. Unfortunately, most event supervisors may not be as knowledgeable about differentiating these two minerals. Both have similar density, luster, hardness, uneven fracture, etc.

If you have a freshly broken specimen, Chalcopyrite will be golden yellow, and Bornite coppery brown. However, I don't feel it fair to ask for identification of these two minerals without providing some information that can be used to distinguish them, such as the formula, or information about the unoxidized color, etc.

Gary Vorwald
2018 National Supervisor
Rocks & Minerals C

Thank you for noticing this as this has been one of the mix ups that both the Div B students I coach and I worry about. I look forward to another great test this year!

[Pomegranate]

Not sure where to ask this, but does anyone remember how long you had at each station for the Nationals Rocks test Div C last year? Thanks!

[fabishkf]

Buy the tests. 3 min (tho I was in div b last year, you can buy the tests), 16 stations.