Rocks and Minerals by UTH Rocks and Minerals by UTH    

Lesson 8: Physical Properties: Streak

Directions

Study the lesson for one week.

Over the week:

• Read the lesson.
• Review the synopsis.
• Recite aloud the vocabulary words and their definitions.
• Study the rock and mineral of the week.
• Complete the enrichment activities.
• Study the review questions.

Synopsis

Rocks and minerals may be identified by one or more of their physical properties. Another identifying physical property of rocks and minerals is streak. Streak is the color of the powder of a rock or mineral left after it is scratched against a surface.

Vocabulary

Physical Property: Characteristics of matter not involving a change in chemical composition.
Streak: The color of the powder of a rock or mineral left after it is scratched against a surface.
Vitreous: Of or resembling glass.
Luminesce: To give off light.

Rock or Mineral of the Week

Overview

• Sodalite was discovered in Greenland in 1811.
• Sodalite is a beautiful royal blue mineral, often used as a decorative gemstone.
• Sodalite may also be used for sculpture and building material.

Physical Characteristics

• Color: Royal blue with white veins
• Hardness: 5.5-6
• Luster: Vitreous (glass-like) to greasy
• Cleavage: Poor, uneven
• Streak: White to bluish
• Tenacity: Brittle

Locations:

• United States (Maine, Arkansas)
• Namibia
• Canada
• Russia
• Greenland

Interesting Facts

• Sodalite is known as the 'wisdom stone,' and some people believe it helps with concentration.

• Sodalite is used to make jewelry.

• Sodalite luminesces under ultraviolet (UV) or fluorescent light.
• Some types of sodalite change color upon exposure to sunlight - for example, from violet to grayish white or from white to pink-red.

Enrichment

Activity 1: Narrate the Lesson

• After reading or listening to the lesson, narrate the lesson aloud using your own words.

Activity 2: Can You Find It?

Find the following elements on the periodic table:

• Sodium (Na)
• Aluminum (Al)
• Silicon (Si)
• Oxygen (O)
• Chlorine (Cl)
• In which group and period is Chlorine (Cl)?

Activity 3: Map the Lesson

• Find Maine (ME) and Arkansas (AR), locations you might find sodalite in the United States.

• Sodalite is also found in Namibia, Canada, Russia, and Greenland.
• Zoom in to find these countries on the map of the world.

Activity 4: Take a Nature Walk

• Embark on a nature walk.
• Collect one rock or mineral specimen.
• Use the gathered specimen to create the field book entry.

Activity 5: Complete a Field Book Entry   

After your nature walk, complete page 6 in 'Fifth Grade Science Rocks and Minerals Notebook Pages.'

Review

Question 1

Is streak a physical property or a chemical property?

1 / 4

Answer 1

Streak is a physical property, for it does not involve a change in chemical composition.

1 / 4

Question 2

Describe something about sodalite (Na8(Al6Si6O24)Cl2).

2 / 4

Answer 2

Sodalite is a striking blue mineral used in jewelry, art, and architecture.

2 / 4

Question 3

Is sodalite (Na8(Al6Si6O24)Cl2) a compound?

3 / 4

Answer 3

Yes, sodalite (Na8(Al6Si6O24)Cl2) is a compound containing more than one type of element.

3 / 4

Question 4

How many different elements does sodalite (Na8(Al6Si6O24)Cl2) contain?

4 / 4

Answer 4

Sodalite (Na8(Al6Si6O24)Cl2) contains five types of elements - Sodium (Na), Aluminum (Al), Silicon (Si), Oxygen (O), and Chlorine (Cl).

4 / 4

❮ ❯

1. Is streak a physical property or a chemical property? Streak is a physical property, for it does not involve a change in chemical composition.
2. Describe something about sodalite (Na8(Al6Si6O24)Cl2). Sodalite is a striking blue mineral used in jewelry, art, and architecture.
3. Is sodalite (Na8(Al6Si6O24)Cl2) a compound? Yes, sodalite (Na8(Al6Si6O24)Cl2) is a compound containing more than one type of element.
4. How many different elements does sodalite (Na8(Al6Si6O24)Cl2) contain? Sodalite (Na8(Al6Si6O24)Cl2) contains five types of elements - Sodium (Na), Aluminum (Al), Silicon (Si), Oxygen (O), and Chlorine (Cl).

References

'Streak (mineralogy).' Wikipedia. en.wikipedia.org/wiki/Streak_(mineralogy). n.p.

'Sodalite.' Wikipedia. en.wikipedia.org/wiki/Sodalite. n.p.

Cited Physical Properties. Geology.com. geology.com/rocks. n.p.