Question

how does quartz look during the formation

Answer 1

Short answer: quartz doesn’t look like a single thing during formation — its appearance depends on the environment and growth rate. Common visual cues you might see as quartz forms are euhedral six‑sided prisms with pointed terminations, cloudy or banded zones from trapped fluids or changing chemistry, tiny drusy crystals lining cavities, and microcrystalline botryoidal or banded textures (chalcedony/agate) when growth is very fine-grained.

More detail, by stage and environment

- Nucleation (very early)
- tiny, sub‑millimeter silica grains or tiny crystal faces forming on a substrate.
- often a powdery or sugary look at microscopic scale; under a hand lens you may see pinpoints of glassy sparkle.

- Crystal growth in open cavities / hydrothermal veins (slow growth)
- crystals commonly grow as clear to smoky/amethyst six‑sided prisms terminated by pyramids (euhedral crystals).
- faces are glassy and often show fine growth striations parallel to the prism.
- growth zoning or “phantoms”: faint internal outlines of earlier crystal shapes where growth paused and resumed.
- fluid inclusions and tiny trapped bubbles give cloudy bands or milky cores.

- Rapid growth or unstable conditions
- skeletal, dendritic, or “hopper” crystal shapes (hollows or stepped faces).
- microcrystalline, fibrous radiating aggregates (spherulites) if growth is fast or silica supply is high.

- In cavities and geodes
- drusy surfaces: many small, glittering crystals carpeting a cavity.
- central larger crystals with smaller crystals around them.

- Silica precipitation at low temperature / diagenesis (chalcedony, agate, jasper)
- microcrystalline, silky or waxy luster; banding (agate) from rhythmic changes in solution chemistry.
- botryoidal (grape‑like) or concentric layering textures.

Why appearance varies
- Growth rate: slow → large clear crystals; fast → small, skeletal, or fibrous crystals.
- Chemistry/impurities: Fe gives amethyst or citrine hues when combined with radiation/heat; other inclusions make colors or cloudiness.
- Trapped fluids or other minerals cause inclusions, banding, and phantoms.
- Temperature and pressure control crystal size and habit.

If you mean a particular setting (e.g., hydrothermal veins, pegmatites, geodes, or sedimentary chert), tell me which and I’ll describe what quartz typically looks like there or show photos/illustrations.