Geology is a large and diverse Jeopardy! topic with approximately 1,357 clues and 13 Final Jeopardy appearances. The topic breaks down into clear sub-areas: Gems & Jewelry (510 clues, 38%), General Geology (368, 27%), Rocks & Minerals (312, 23%), Volcanoes (122, 9%), and Fossils (45, 3%).
The dominant categories are "GEOLOGY" (336 clues), "ROCKS & MINERALS" (235), "GEMS & JEWELRY" (187), "GEMS" (166), and "VOLCANOES" (96). The topic is heavily weighted toward gemstone identification, know your gems and you'll nail nearly 40% of Geology clues.
Top answers: turquoise (23), marble (20), jade (20), pearls (19), sedimentary (18), quartz (18), diamond (13), graphite (12), amethyst (12), amber (12), emerald (11), slate (10), limestone (10), coal (10), aquamarine (10), anthracite (10).
Study strategy: This is a "know the properties" topic. For gems: color, hardness, origin, and cultural associations. For rocks: type classification (igneous/sedimentary/metamorphic), key examples, and formation processes. For volcanoes: famous eruptions, locations, and terminology.
Key stumpers: Kilauea (71% wrong!), basalt (60%), anthracite (40%), asbestos (40%), granite (38%), graphite (36%), opal (40%), quartz (31%).
Gemstones account for 38% of all Geology clues. The show tests color, hardness (Mohs scale), origins, cultural significance, and birthstone associations.
23 appearances · 86% correct
An opaque blue-green gemstone with deep cultural significance to Native American peoples, especially the Navajo and Zuni. Apache people associated it with the rainbow's end and believed it aided them in battle. "Howlite" dyed blue to imitate turquoise is sold as "turquenite."
20 appearances · 79% correct
A green gemstone with two mineral forms: nephrite (more common) and jadeite (rarer, more valuable). Revered in Chinese culture for thousands of years. During the Han dynasty, Chinese royals were buried in jade suits. Ancient scholar Hsu Shen gave it "five human virtues."
19 appearances · 100% correct (never missed!)
Organic gems produced by oysters and mollusks. Kokichi Mikimoto developed cultured pearls in 1893. Types include Akoya (Japan, various hues including pink and cream) and white South Sea (Australia). A "pearl of great price" is a biblical parable.
Combined ~30 appearances · 85-100% correct
The hardest natural substance, scoring 10 on the Mohs scale. Made of pure carbon. South Africa and Namibia are major producers. "Fancies" (colored diamonds) sell for over $1 million per carat. The De Beers company dominates the industry. The "Uncle Sam" (40.23 carats) is the largest diamond found in the U.S. (Arkansas).
12 appearances · 92% correct
A purple variety of quartz. February's birthstone. South Carolina's state gemstone. The Empress of Uruguay is a nearly 11-foot-tall amethyst geode weighing 2.75 tons.
12 appearances · 100% correct
Fossilized tree resin (not a mineral). Often contains preserved insects, especially specimens from the Dominican Republic. Has one of the lowest densities among gems, often floats in salt water. A 15-23 million-year-old scorpion was found in Mexican amber.
20 combined appearances · 88-91% correct
A green variety of beryl. Colombia's Muzo mine produces yellowish-green; Chivor mine produces bluish-green. Inclusions that cloud the stone are called "jardin" (French for "garden") and are actually considered desirable. A 75-carat emerald once worn in a sultan's belt buckle is now in the Smithsonian.
10 appearances · 70% correct
A blue-green variety of beryl (same mineral family as emerald). Name means "water of the sea" in Latin.
9 appearances · 88% correct
A deep blue gemstone. Pliny the Elder called it "a fragment of the starry firmament." The blue color comes from the mineral lazurite. Name is from Latin and Persian for "blue stone."
Sedimentary (18 appearances, 81% correct): Formed from accumulated deposits, either on land or underwater. Cementation is the last stage of formation. The type where you'll mainly find fossils. Examples: limestone, shale, sandstone, chalk.
Igneous (often clued in Science topic): Formed from cooled magma or lava. Examples: granite, basalt, obsidian, pumice.
Metamorphic: Formed by heat and pressure transforming existing rocks. Examples: marble, slate, quartzite, schist.
20 appearances · 80% correct
A metamorphic rock formed from limestone under heat and pressure. Italy's Carrara quarries are world-famous (used by Michelangelo for his Pieta and David). Varieties include Botticino, Calacatta, and Statuario (slightly translucent, used in fine statuary).
18 appearances · 69% correct, somewhat tricky
The most common mineral in Earth's crust. When clear and colorless, called "rock crystal." Used in kitchen countertops. Crystals keep accurate time (quartz watches). The "quartz crisis" of the 1970s disrupted Swiss watchmaking. Would score minimum 24 points in Scrabble.
12 appearances · 64% correct, STUMPER (36% wrong) · 1 FJ appearance
A mineral form of carbon. Mixed with clay, it makes pencil "lead." Mines near Ticonderoga, New York were once the USA's principal source. Soft and slippery (used as a lubricant). Same element as diamond but different crystal structure.
10 appearances · 80% correct
A fine-grained metamorphic rock that splits into flat layers. Used for roofing, chalkboards, and floor tiles.
10 appearances · 86% correct
A sedimentary rock composed mostly of calcium carbonate. Formed from oceanic ooze or accumulated shells/coral. Varieties include chalk and tufa. Fossil-rich.
10 appearances · 60% correct, STUMPER (40% wrong)
The highest grade of coal, composed almost entirely of carbon. Hard, shiny, and burns with little smoke. Distinguished from bituminous (soft) coal.
9 appearances · 63% correct, STUMPER (38% wrong)
A coarse-grained igneous rock. Very common in the Earth's crust. Used in construction and monuments. Mount Rushmore is carved from it.
Volcanoes account for 122 clues (9% of the topic), mostly from the "VOLCANOES" category (96 clues).
7 appearances · 29% correct, THE #1 STUMPER (71% wrong!)
A shield volcano on Hawaii's Big Island and one of the world's most active volcanoes. Despite being one of the most famous volcanoes in the world, contestants get it wrong 71% of the time. Often confused with Mauna Loa or other Hawaiian volcanoes.
8 appearances · 100% correct
See the Mountains guide for full coverage. Destroyed Pompeii (79 AD). Never missed in the Geology topic.
A frequently tested concept. Know the endpoints and key reference points:
| Hardness | Mineral | Memory Hook |
|---|---|---|
| 1 | Talc | Softest (talcum powder) |
| 2 | Gypsum | |
| 3 | Calcite | |
| 4 | Fluorite | |
| 5 | Apatite | |
| 6 | Orthoclase | |
| 7 | Quartz | Scratches glass |
| 8 | Topaz | |
| 9 | Corundum | Ruby/Sapphire |
| 10 | Diamond | Hardest (perfect 10) |
| Year | Answer | Theme |
|---|---|---|
| 1984 | rubies | "Most expensive gems carat for carat" |
| 1987 | (3 of) HI, AK, WA, OR, CA | Active U.S. volcanoes |
| 1990 | South Africa & USSR | Gold production leaders |
| 1993 | a sapphire | "Star of India is one of these" |
| 1998 | Andes | "5 highest volcanoes on Earth" |
| 1998 | Australia | "Only continent with no active volcanoes" |
| 1999 | Iron | "Nutrient Americans most likely deficient in" |
| 1999 | San Andreas Fault | "800-mile feature discovered by Lawson" |
| 1999 | Folic acid | "Vitamin from Latin for leaf" |
| 2001 | Hawaii | "State with active volcanoes farthest south" |
| 2005 | Indonesia | "2/3 of all volcano deaths in 400 years" |
| 2006 | graphite | "8-letter mineral from Ticonderoga mines" |
| 2023 | Iceland | "Walk along tectonic plate boundaries" |
FJ themes: Volcano geography (which country/state/continent), gem superlatives (most expensive, famous specimens), and mineral identification. The show loves "only continent without" questions.
| Answer | Wrong % | Memory Hook |
|---|---|---|
| Kilauea | 71% | Hawaiian shield volcano; world's most active |
| basalt | 60% | Dark igneous; most common rock in Earth's crust |
| anthracite | 40% | HARD coal (vs. bituminous = soft coal) |
| asbestos | 40% | Fire-resistant fibrous mineral; carcinogenic |
| opal | 40% | "Play of color"; Australia's national gem |
| lava | 40% | Magma above ground = lava |
| granite | 38% | Coarse igneous; Mount Rushmore; countertops |
| graphite | 36% | Carbon mineral; pencil "lead"; Ticonderoga |
| shale | 33% | Fine sedimentary; fracking source |
| pumice | 33% | Volcanic rock that floats |
| quartz | 31% | Most common mineral; watches; countertops |
These are free points, never miss them: - Pearls (19x, 100%): Cultured by Mikimoto; organic gem - Amber (12x, 100%): Fossilized resin; contains insects - Vesuvius (8x, 100%): Destroyed Pompeii - Diamond (8x, 100%): Hardest; Mohs 10; carbon - Iron (6x, 100%): Earth's core - Flint (6x, 100%): Fire-starting stone - Green (7x, 100%): Color of emeralds/jade
| Color | Gem |
|---|---|
| Blue-green (opaque) | Turquoise |
| Green (translucent) | Emerald, Jade |
| Purple | Amethyst |
| Deep blue | Lapis lazuli, Sapphire |
| Red | Ruby, Garnet |
| Yellow-orange | Amber, Topaz, Citrine |
| Play of color | Opal |
| Blue-green (transparent) | Aquamarine |
| Clear | Diamond, Rock crystal (quartz) |
Memorize these and recognize 31.2% of all Geology clues.
| # | Answer | Count | Sample Clue |
|---|---|---|---|
| 1 | the topaz | 23 | The astronomer carefully adjusted the top azimuth of his telescope made of this |
| 2 | the pearl | 23 | The waters of the Persian Gulf are an important source of this gem |
| 3 | a diamond | 22 | April is said to be cruel, but it also be expensive as the pink star version of this birthstone sold for $71.2 million in 2017 |
| 4 | turquoise | 21 | Big in the Southwest, it's one of the birthstones for December |
| 5 | the emerald | 18 | L. Frank Baum's birthstone, it's found in the name of a fictional place he created |
| 6 | the amethyst | 17 | Princess Stephanie of Monaco was born to the purple, so it's fitting that this is her birthstone |
| 7 | a ruby | 16 | Chrome & iron are what give this, red corundum, its color |
| 8 | pearls | 14 | Organic & opaque, they represent purity & virginity |
| 9 | Jade | 14 | In Taoism, Yudi is known as this green gemstone Emperor & is often depicted holding a tablet of it |
| 10 | a garnet | 14 | Montana & Cape rubies are actually this January birthstone |
| 11 | sedimentary | 13 | One of the 3 main types of rock, it's formed by the buildup of material either on land or underwater |
| 12 | quartz | 13 | Onyx, jasper & agate are varieties of this mineral |
| 13 | marble | 13 | Botticino & Calacatta are Italian varieties of this metamorphic rock |
| 14 | aquamarine | 13 | March swims in with this pale greenish blue birthstone; one healthy specimen from Brazil weighed nearly 250 pounds |
| 15 | a sapphire | 13 | It may surprise you that Montana is a good place to find this blue September birthstone |
| 16 | the opal | 12 | If the water in this October gem dries out, the rainbow colors will disappear |
| 17 | diamonds | 11 | Group which had the following, their biggest hit in 1957: "Ah, ya ya ya ya, ya ya ya ya, ya ya ya ya / Little darling oh little darling" |
| 18 | emeralds | 10 | Fashioned in 1593, the crown of the Andes is set with 453 of these May birthstones, including the 45-carat Atahualpa |
| 19 | rubies | 9 | The Bible tells us "The price of wisdom is above" these red gems, July's birthstone |
| 20 | limestone | 9 | Caves eroded by water are most commonly found in this type of rock composed mainly of calcium carbonate |
| 21 | lapis lazuli | 9 | Stone of Laz, the Arabian goddess of love |
| 22 | graphite | 9 | German geologist Abraham Werner gave this mineral its name, derived from a Greek word for "to write" |
| 23 | coal | 9 | Rudolf Diesel's first engine was designed to run on the dust of this solid fuel |
| 24 | pumice | 8 | This lightweight, porous volcanic rock is used in concrete & plaster as well as in abrasives & scouring compounds |
| 25 | asbestos | 8 | Fireproof but unhealthy: OBSESS AT |
| 26 | amber | 8 | According to Guinness, the largest example of this fossil resin gem weighs 33 pounds 10 ounces |
| 27 | Vesuvius | 7 | Pliny the Elder, Roman geologist, died while observing this volcano erupting |
| 28 | green | 7 | The gemstone known as Brazilian emerald is actually a tourmaline of this color |
| 29 | earthquakes | 7 | Seismology is the study of this |
| 30 | Antarctica | 7 | In 1986 dinosaur fossil remains were first discovered on this continent |
| 31 | slate | 6 | Intense pressure on shale turns it into this "blackboard" material |
| 32 | Mammoth Cave | 6 | "Always stay with the tour group" is one of the rules at this "really big" cave system in Kentucky |
| 33 | flint | 6 | Striking this hard form of quartz with steel produces a spark |
| 34 | emery | 6 | Corundum makes up much of this rock used to make an abrasive "board" |
| 35 | a glacier | 6 | Made up of material ranging from boulders to sand, a moraine is debris carried & deposited by one of these masses over time |
| 36 | the mantle | 6 | This layer of the Earth makes up more than 80% of its volume |
| 37 | South Dakota | 5 | Located in the Black Hills region of this state, Wind Cave National Park boasts 160 miles of explored cave passageways |
| 38 | South Africa | 5 | The best tiger's-eye comes from Griqualand West in this country also known for its diamonds |
| 39 | shale | 5 | A type of natural gas is named for this 5-letter rock, one of the most common types of sedimentary rock |
| 40 | opals | 5 | Australia produces some of the finest examples of these gems |
| 41 | Mount St. Helens | 5 | Soon after this volcano erupted in 1980, the city of Spokane was plunged into darkness due to the ash |
| 42 | magma | 5 | Before it reaches the surface & goes blooey, lava is known as this |
| 43 | iron | 5 | Limonite, hematite & magnetite are all ores of this metal |
| 44 | Iceland | 5 | In this nation of 360,000 people, you can walk along the boundaries of the Eurasian & North American tectonic plates |
| 45 | granite | 5 | This commonest coarse-grained plutonic rock is desirable for countertops |
| 46 | caves | 5 | J. Harlen Bretz explored many of these with his dog; in his book, these "of Missouri", he called them "valleys with roofs" |
| 47 | anthracite | 5 | Also called hard coal, it burns without smoke |
| 48 | agate | 5 | Fine-grained quartz used to make an aggie marble |
| 49 | Africa | 5 | The diamond known as the "Star of" this continent is set in the British royal scepter |
| 50 | water | 5 | Opal & turquoise are found mostly in parts of world where there is little of this |
These appear 8+ times. Memorize these first.
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