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Geology, 
explained.

Clear essays and videos on how the Earth actually works.

FOLDFAULTDYKEUNCONFORMITY01 — DEPOSITION02 — FOLDING03 — FAULTING04 — INTRUSION05 — EROSION06 — NEW DEPOSITIONTODAYREAD THE EARTH

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Hello! I make Geoscopy: videos and long-form essays about how the Earth actually works. The geology I grew up reading was either locked in textbooks nobody outside the field opens, or chopped into 30-second clips that miss the point. Geoscopy is what I wanted instead: the real science, explained clearly, without oversimplifications.

There’s 4.5 billion years of history under your feet. I’d like to teach you to read it.

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Specimen of the weekMineral · Phosphates

Apatite

Apatite is not just one neat mineral with one fixed composition. In everyday mineral collecting and geology, “apatite” is often used for a group of related calcium phosphate minerals.

Mohs hardness
5. Apatite is the reference mineral for hardness 5 on the Mohs scale.
Common simplified formula
Ca5(PO4)3(F, Cl, OH). The main end-members are fluorapatite, hydroxylapatite, and…
Crystal system
Hexagonal for the common apatite-group minerals.

Open the specimen

Polished watermelon tourmaline slice with pink, yellow, and green bands

Tourmaline

Transparent barite crystal cluster on pink mineral matrix

Barite

Rough translucent red garnet gemstone on black background

Garnet

Green fluorite crystal on yellow mineral matrix

Fluorite

Translucent brown and amber feldspar crystals (feldspar specimen)

Feldspar

Green and yellow banded metamorphic rock specimen (gneiss sample)

Gneiss

Fossilized fish fin embedded in a gray rock slab (limestone)

Limestone

Cluster of shiny brown layered mica crystals on black background

Mica

Golden-yellow crystal cluster with elongated translucent mineral prisms (borax mineral specimen)

Borax

Orange and gray crystal mineral cluster specimen (monazite mineral)

Monazite

Pink mineral crystal resting on a green stone prism (apatite)

Apatite

Dark green pyroxene crystal cluster on matrix

Pyroxene

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