Lily wrote to us and asked about the mineral amethyst. Specifically, she wants to know what gives amethyst that beautiful purple color. In this video, we talk about why amethyst is purple, its relation to quartz and an interesting fact about how citrine fits into that mineral family.
This week I am answering a question that I received from two readers, Alliondra and Alexandria. Their questions were so similar that I thought I would answer them together. They want to know:
Can I be a geologist some day and how can I make my dreams of becoming a geologist easier? In this video, I’ll tell you a little secret about how I came to be a geology major in college along with some tips on things you can do to prepare for college and your career.
Cory wrote to us and asked: What rocks are changed by high pressure and high temperature? Metamorphic rocks are the rocks that change either physically or chemically by heat and pressure. The term metamorphic comes from the Greek words “meta” which means change and “morph” which means form. Metamorphism is a solid state change meaning that the minerals within the rock recrystallize in response to heat, pressure and the chemical reaction with hot fluids without melting the original rock.
Ellie wrote to us and asked what notes she should take when she finds rocks and minerals. Geologists use fancy notebooks with waterproof paper but a simple notebook and pen will work just fine. Watch this video to find out what notes to take and how to organize your notebook for your collection.
Several of our readers have written to us and asked: How do you clean streak plates? In case you are not familiar with streak plates, they are little pieces of unglazed porcelain tile that you use to test the streak color of a mineral. There are black streak plates and white streak plates. You use the black plates for light-colored minerals and white plates for dark-colored minerals. To test the streak, you rub the mineral across the streak plate and see what color shows up on the plate. That is the streak or the color of the mineral in powdered form. When you do the test you need to rub hard on the streak plate because you are trying to crush part of the sample into a fine powder. Over time the plates will become dirty and you will want to clean them.
Fossils are the remains or impressions of once living organisms that you can find in sedimentary rocks. There are two basic types of fossils that geologists and paleontologists talk about. These are body fossils and trace fossils. Body fossils are a real body part of an animal such as a dinosaur bone or a shark tooth. A trace fossil is something that shows evidence that something was there such as tracks, burrows, trails, molds, casts, and impressions.