About Curriculum

    Rocks and Minerals by UTH Rocks and Minerals by UTH    

Lesson 30: Stalactites and Stalagmites


Stalactites and stalagmites are secondary mineral deposit of calcium carbonate or another mineral, in shapes similar to icicles. Stalactites hang from the roof of a cave. They form as mineral-rich water drips from a cave roof. As the water drips, some of the minerals precipitate out of the water to form the stalactite.
Stalactites Forming on the Cave Roof
Stalagmites project upward from the ground of a cave. Like stalactites, stalagmites form when minerals precipitate out of water. As water drips from the roof of the cave and hits the floor, some of the minerals precipitate out, forming the stalagmite.
Stalagmites Forming on the Cave Ground
Here is an easy way to distinguish between stalactites and stalagmites.

  • Stala-C-tites, have a "C" for "Ceiling" as they grow down from the cave ceiling.
  • Stala-G-mites, have a "G" for "Ground" as they grow up from the cave ground.

At times stalactites and stalagmites fuse together at their tips to form columns within caves. Point out the stalactites, stalagmites, and columns in the image below.
Stalactites, Stalagmites, and Columns
Stalactites and stalagmites are most commonly made from limestone rock.
If you ever visit a cave, do not touch the stalactites and stalagmites. The oils on human skin may interfere with the growth process. It takes a very long time for stalactites and stalagmites to grow. The average growth rate is around half an inch every 100 years, although the fastest can grow a little more than an inch in 10 years.
Exploring a Tunnel

    Rocks and Minerals by UTH Rocks and Minerals by UTH    

Lesson 30: Stalactites and Stalagmites

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

Stalactites and stalagmites are secondary mineral deposits of calcium carbonate or other minerals, in shapes similar to icicles. Stalactites hang from the roof of a cave, and stalagmites project upward from the ground of a cave.

Vocabulary

Cave: A large, naturally-occurring cavity formed underground or in the face of a cliff or a hillside.
Stalagmite: A secondary mineral deposit of calcium carbonate or other mineral, in shapes similar to icicles, that grows up from the ground of a cave.
Stalactite: A secondary mineral deposit of calcium carbonate or another mineral, in shapes similar to icicles, that hangs from the roof of a cave.

Rock or Mineral of the Week

  • Dolomite is another mineral commonly associated with caves.
  • Dolomite is a saline evaporite consisting of a mixed calcium and magnesium carbonate, with the chemical formula CaMg(CO3)2.

Physical Characteristics
  • Color: Often white, but other colors as well
  • Hardness: 3.5-4
  • Luster: Vitreous to pearly
  • Cleavage: Three directions
  • Streak: White
  • Tenacity: Brittle

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:

  • Calcium (Ca)
  • Magnesium (Mg)
  • Carbon (C)
  • Oxygen (O)
  • In which group and period is magnesium (Mg)?

Activity 3: 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 4: Complete a Field Book Entry   

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

Review

Question 1

Describe something about dolomite.
1 / 3

Answer 1

Dolomite is a mineral of calcium and magnesium carbonate commonly associated with caves.
1 / 3

Question 2

Which grows up from the ground of a cave - stalactites or stalagmites?
2 / 3

Answer 2

Stalagmites grow up from the ground of a cave.
2 / 3

Question 3

Which grows down from the ceiling of a cave - stalactites or stalagmites?
3 / 3

Answer 3

Stalactites grow down from the ceiling of a cave.
3 / 3

  1. Describe something about dolomite. Dolomite is a mineral of calcium and magnesium carbonate commonly associated with caves.
  2. Which grows up from the ground of a cave - stalactites or stalagmites? Stalagmites grow up from the ground of a cave.
  3. Which grows down from the ceiling of a cave - stalactites or stalagmites? Stalactites grow down from the ceiling of a cave.

References

  1. 'Dolomite.' Wikipedia. en.wikipedia.org/wiki/Dolomite_(mineral). n.p.
  2. 'Stalagmite.' Wikipedia. en.wikipedia.org/wiki/Stalagmite. n.p.
  3. 'Stalactite.' Wikipedia. en.wikipedia.org/wiki/Stalactite. n.p.
  4. Cited Physical Properties. Geology.com. geology.com/rocks. n.p.

Contact  Privacy Policy  Terms of Use © 2023 Under The Home Online Homeschool Curriculum
Contact      Privacy      Terms
youtube icon twitter icon pinterest icon facebook icon
© 2023 Under The Home