"Which five minerals do you think are the most important ones to know, and why? In other words, if you had to introduce a non-geologist to just five of the earth's multitudinous building blocks, which ones would you choose to share, and offer a justification for each."
I am thinking along the same lines as some of the others who have responded, so some of these may not be very original...and I am also thinking along the lines of introducing minerals to a non-geologist and what they could take away from learning these 5. I feel like my "whys?" are a bit lame, I apologize ahead of time:
- Quartz: It's every where! People even worship it (not sure why). Its very common, so easy to show in different mineral states and rocks; and who can forget SiO2. The different colors make it easy for a non-geologist to enjoy and remember also.
- Calcite: Easy - caves, fossilization and invertebrates. Heck, trilobites used calcite for their eye lenses! Its fun!
- Feldspar: The most common mineral in the earths crust, easily recognizable, & found in igneous, metamorphic and sedimentary rocks. Of course plagioclase feldspars are also one of my favorites so I might be a little partial here.
- Magnetite: People are always amazed by this one - the magnetic properties surprise people and they will play with it forever. Its a iron ore, and can be found in banded iron formations, and something fun - "Crystals of magnetite have been found in some bacteria (e.g., Magnetospirillum magnetotacticum) and in the brains of bees, of termites, of some birds (e.g., the pigeon), and of humans. These crystals are thought to be involved in magnetoreception, the ability to sense the polarity or the inclination of the Earth's magnetic field, and to be involved in navigation. Also, chitons have teeth made of magnetite on their radula making them unique among animals. This means they have an exceptionally abrasive tongue with which to scrape food from rocks." [link] Now, wasn't that fun?
- Clays: They make foods I like hold together better so I can eat them (chocolate, ice cream...), they are used in makeup, paint, toothpaste, ceramics..... How cool is that. They are stable, platy, like to stay suspended and stick to my cars paint. Clay rocks.