
ScottMaurer19 wrote:Anyone else notice that crystalline limestone is not on the official list anymore
Kyanite wrote:ScottMaurer19 wrote: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 wrote:Kyanite wrote:ScottMaurer19 wrote: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
gvorwald wrote: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
Pomegranate wrote: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!
kate! wrote:Pomegranate wrote: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!
Never been to nats, nor am I div C, but I do have experience with the proctor (Gary Vorwald) and his stations are typically 2 minutes long. They might be longer for nationals though, but expect somewhere in that range.
dxu46 wrote:kate! wrote:Pomegranate wrote: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!
Never been to nats, nor am I div C, but I do have experience with the proctor (Gary Vorwald) and his stations are typically 2 minutes long. They might be longer for nationals though, but expect somewhere in that range.
gvorwald: Did you only write division C for last year nats?
kate! wrote:For the sedimentary rocks in Fossils, can we just use our notes from this event?
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