A、They are difficult to find. B、Their color is unique. C、They are found in volcanic rock. D、Their size is impressive. A“plagiocl

I’d like to begin by thanking Dr. Kane for inviting me to be here today. Although I’m not a geologist, I have been collecting minerals for years. My collection is really diverse because I’ve traveled all over the world to find them. Today I’ve brought a few specimens for you to see. After I discuss each one, I’ll pass it around so that you can look at it more closely.
    As you know, feldspars are the most abundant minerals and are divided into a number of types. These first samples are orthoclase’s. Notice that they vary in color from white to pink to red. This glassy one is found in volcanic rock-in fact, I found it in New Mexico on a collecting trip.
    This next sample that I’ll pass around is a microcline mineral—also called amazons tone. You can identify it by its bright green color. It’s often used in jewelry and really is quite attractive.
    These final samples are all plagioclase feldspars. Many plagioclases are very rare, so I’m particularly proud of the variety in my collection.
    I’ve also brought a few slides of some larger mineral samples, and if you’ll turn out the lights now, I’d like to show them to you.
5. What are the student doing as they listen to the speaker?
6. How did the speaker acquire all her minerals?
7. Why is the speaker proud of her plagioclase feldspars?