Mineral Identification Challenge

Scientific concepts & nature phenomena presented

Mineral identification using physical properties

An Earth science reference table summarizes diagnostic physical properties, including:

• Luster (e.g., metallic vs. nonmetallic; greasy feel)
• Hardness (measured with the Mohs hardness scale, e.g., 1–2, 2–2.5, 2.5–3, 3.5, 5–6, 5.5–6.5, etc.)
• Cleavage (including cleavage in four directions)
• Fracture (e.g., “extremely dense,” plus additional notes such as an “ore of iron” with a stated hardness range)
• Streak testing (the powder color produced when rubbed on a streak plate)
• Chemical reactivity tests (e.g., acid causes bubbling)
• Odor test (e.g., “rotten eggs” indicating sulfur-bearing minerals)
• Physical habit/shape (e.g., flexible thin sheets; striations)

Mineral composition (elements/chemistry)

Chemical composition is used as diagnostic evidence, including minerals containing:

• Carbon, magnesium, iron, sodium, chlorine, fluorine, oxygen, and others.

Reference-resource approach

The video instructs viewers to use a mineral characteristics table—typically listing:

• luster
• hardness
• cleavage/fracture
• color
• composition
• uses

…and match observed samples to mineral identities.

Mineral identification challenge (samples) — key properties noted

Note: Names are explicitly given only for some samples; others are described by properties.

• Sample 1: Metallic luster; extremely dense
• Sample 2: Iron ore; fracture; hardness 5.5–6.5
• Sample 3: Brassy yellow color; fracture; greenish-black streak
• Sample 4: Extremely soft; greasy feel
• Sample 5: Hardness 1–2; cleavage; composed of carbon
• Sample 6: Odor of “rotten eggs”; hardness 2; “native mineral” (single element)
• Sample 7: Cleavage; hardness 2–2.5; breaks into flexible thin sheet
• Sample 8: Commonly used in drywall; very easily scratched
• Sample 9: Hardness 2.5–3; cleavage; flexible sheets
• Sample 10: Acid test bubbles; commonly used in cement
• Sample 11: Contains magnesium; hardness 3.5; shows cleavage
• Sample 12: Visible striations; hardness 6; shows cleavage
  • (The label “and it two” appears to be a transcription error.)
• Sample 13: Hardness 5–6; commonly called augite
• Sample 14: Contains carbon and fluorine; cleaves in four directions
• Sample 15: Contains iron; shows fracture
• Sample 16: Commonly used in ceramics; shows cleavage
• Sample 17: Used in electronics; hard; shows fracture
• Sample 18: Used in jewelry; nonmetallic luster
• Sample 19: Cubic cleavage; contains sodium and chlorine
• Sample 20: Streak leaves reddish-brown powder; contains iron and oxygen
• Sample 21: Complex composition; may cleave at approximately 56° angles

Methodology / procedure outlined

• Use the mineral characteristics table (e.g., luster, hardness, cleavage/fracture, streak, color, composition, uses).
• After each image, pause and examine clues, including:
  • visible color
  • luster
  • other observable features (e.g., striations, sheet-like habit)
• Apply diagnostic tests mentioned:
  • Streak test (powder color)
  • Hardness test (Mohs scale)
  • Acid test (bubbling)
  • Odor test (“rotten eggs”)

Researchers or sources featured

• NASA Science — referenced via science.nasa.gov
• New York State Earth Science Reference Tables — referenced as a table containing “common minerals on earth”