GIZMOS Student Exploration Mineral Identification

Exam (elaborations) GIZMOS Student Exploration Mineral Identification Student Exploration: Mineral Identification Vocabulary: crystal, density, hardness, homogeneous, luster, mass, mineral, streak, volume Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Suppose you find a yellow piece of metal in a stream. How could you tell if it is real gold? The real gold would not be magnetic, while fake gold would be. 2. In the city a street peddler offers to sell you a diamond ring for thirty bucks. How could you test if the rock in the ring is a real diamond? The diamond would not be able to be scratched by a simple material. Gizmo Warm-up: Determining density A mineral is a naturally formed crystal. You can identify a mineral by its properties. In the Mineral Identification GizmoTM, under Choose property to test, select Density. 1. Mass is the amount of substance in an object. Drag the mineral sample onto the balance. What is the mass of the mineral? 36.4g (Units are grams, g.) 2. Volume is the amount of space an object takes up. The volume is measured by how much the water rises in a graduated cylinder. Drag the mineral into the cylinder. What is the volume of the mineral? _14 mL (Units are milliliters, or mL.) 3. Density is a measure of how “light” or “heavy” an object is for its size. To find the density of an object, divide the mass by the volume. (Calculators are recommended.) What is the density of the mineral? 2.6 g/mL (Units are grams per milliliter, g/mL.) This study source was downloaded by from CourseH on :28:40 GMT -05:00 GIZMOS Student Exploration Mineral Identification This study source was downloaded by from CourseH on :28:40 GMT -05:00 Question: What properties allow us to identify minerals? 1. Observe: Minerals are made of atoms in a repeating pattern and often form crystals. The shapes of crystals can help identify the mineral. Luster is the way the mineral’s surface reflects light. There are many ways to describe luster, four examples are shown. Color can sometimes be a useful way to identify a mineral, but it is not always reliable. A. Describe the crystal shape of Sample A: Irregular B. Describe its color and luster: Clear, glassy 2. Calculate: Select the Density test. What is the density of Sample A? 2.6 g/mL 3. Measure: Select the Hardness test. Hardness is a measure of how easily a mineral can be scratched. It is measured on a scale of 1 to 10 called Mohs scale. If a mineral scratches a fingernail (hardness 2.5) but not a penny (3.5), its hardness is about 3. A. Drag the mineral sample across each test object. Which objects are scratched? All objects are scratched. B. What is the estimated hardness of the mineral? 5.5 4. Observe: Select the Streak test. The streak is the color of a material’s powder. You can observe the streak by rubbing the mineral across a tile called a “streak plate.” Drag the mineral sample across the streak plate. What color is the streak? (Note: In some cases the streak is colorless and cannot be seen.) colorless 5. Observe: Select the Acid test. Some minerals cause hydrochloric acid to bubble and fizz. Drag the eyedropper of acid over to the mineral. Does the acid fizz? No. 6. Identify: Now it is time to identify the mineral. Look at your Mineral Key. Find a mineral that has properties that match Sample A. Type the name under Mineral name in the Gizmo and press Submit. It may take several guesses to get it right. What mineral is Sample A? Quartz This study source was downloaded by from CourseH on :28:40 GMT -05:00 Goal: Use a key to identify minerals. 1. Collect data: Use the Gizmo to collect data about minerals B through F. Fill in the data table. Sample Crystal shape Color/ Luster Density Hardness Streak Fizzes in acid? B irregular Pink/pearly 2.6 g/mL 4 white no C irregular Glassy/gol