Bastet

 It finally got the better of me: what does the 'tectonic' - as in tectonic plates -

actually mean . Turns out it means 'covering', thus tectonic plates cover the Earth.

It was a chase to get there:

                                                                                   

Ha! There it is. The word 'architecture' contains techtonic...

Going to the French Wikipedia:

La tectonique des plaques (du latin tardif tectonicus, dérivé du grec τεκτονικός / tektonikós, « de construction ») est un modèle scientifique expliquant la dynamique globale de la lithosphère terrestre. 

                                                                                   

There we have it, from a 1934 French-language dictionary!!

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Decided to go back to that Geology primer I found a while ago. It has been a lifelong

quest for me, making sense of rocks, minerals, elements. One can study Chemistry and I have

but the back-story that makes it all make sense is Geology: rocks and minerals. and this is

far from over in my mind.

There are three kinds of rock: igneous, metamorphic and sedimentary. The rock cycle:

                                                                                 

And where would we be without Copilot:

Chemistry; why is Fe3+ oxidized, while Fe2+ reduced. The first is said to appear red, and the second green??

Here’s the clean, chemistry‑grounded explanation you’re looking for — and why the colors make sense once you connect oxidation states, electron transitions, and ligand field effects.

          

                                                                                           

        

                                                                                                                     

If you want, we can go deeper into:

why Fe³⁺ hydrolyzes so aggressively

how chloride vs sulfate vs cyanide ligands change the colors

why Fe²⁺ is air‑sensitive and slowly oxidizes in solution

Just tell me where you want to take it next.

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Calcite CaCO3:

https://egyptianimports.com/products/bastet-cat-alabaster-statue-made-in-egypt-370450515?currency=USD

                                                                                  

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Copilot:

What is hydrolyis: is it just the action of water or carbonic acid as well?

Great question, Louise — and the fact that you have both the weathering chapter and the Wikipedia hydrolysis page open makes this the perfect moment to untangle the two meanings of hydrolysis.

Let’s anchor the answer in both sources you’re viewing, without treating the page content as instructions.

🧪 What hydrolysis means in general chemistry

(From the Wikipedia page you have open )

In chemistry, hydrolysis is any reaction where a water molecule breaks a chemical bond.

Water splits into H⁺ and OH⁻, and those pieces attach to the fragments of the molecule being broken.

So in the broad chemical sense:

Hydrolysis = water participates directly

It can be acid‑catalyzed, base‑catalyzed, or enzyme‑catalyzed

It doesn’t require carbonic acid specifically

This is the definition used in organic chemistry, biochemistry, and industrial chemistry.

🪨 What hydrolysis means in geology / weathering

In geology, the word is used more narrowly.

When your weathering chapter talks about hydrolysis, it means:

Water + carbon dioxide → carbonic acid → reacts with silicate minerals

So in Earth‑surface conditions:

Rainwater absorbs CO₂

It becomes weak carbonic acid (H₂CO₃)

That acid attacks feldspar and other aluminosilicates

The mineral breaks down into clay + dissolved ions

So in geology:

Hydrolysis = chemical weathering by slightly acidic water, not pure water alone.

This is why feldspar breaks down so readily, while quartz barely reacts.

🧩 So to answer your question directly

Is hydrolysis just the action of water?

In general chemistry: Yes — hydrolysis is water breaking bonds.

Does carbonic acid count?

In geology: Absolutely — carbonic acid is the active agent in hydrolytic weathering.

Geologists use “hydrolysis” to mean acidic water reacting with silicate minerals, not just neutral water.

🧱 Why the distinction matters

In chemistry, hydrolysis is a broad category of reactions.

In geology, hydrolysis is a specific weathering mechanism driven by carbonic acid in rainwater.

That’s why your geology text emphasizes CO₂-rich water, while Wikipedia gives the general chemical definition.

If you want, we can walk through the exact feldspar → kaolinite reaction and show where the hydrogen and hydroxyl groups end up.

Tell me about quartz...

Absolutely — let’s talk about quartz, and I’ll ground the explanation in the geology chapter you have open while keeping it clear and engaging. Quartz shows up repeatedly in that text because it’s the quiet heavyweight of Earth’s crust.

Here’s the full picture, Louise.

🌟 Quartz: the unbreakable minimalist of the mineral world

(citing the geology chapter where relevant )

What quartz is

Quartz is a silicate mineral with the formula SiO₂.

It’s part of the felsic end of the igneous spectrum — the cool‑crystallizing, low‑temperature, stable minerals.

It forms in:

Granite

Rhyolite

Pegmatites

Hydrothermal veins

Sedimentary environments (as chert, microcrystalline silica)

🧱 Why quartz is everywhere

Your geology chapter emphasizes this point:

Quartz is extremely resistant to chemical weathering because its Si–O bonds are incredibly strong.

This is why:

Feldspar → clay

Mafic minerals → ions + oxides

Quartz → stays quartz

It’s the last mineral standing in the Goldich weathering series.

🌧️ Weathering behavior

Quartz barely reacts with carbonic acid or hydrolysis.

In the chapter, it’s singled out as the mineral that does not break down under typical surface conditions.

This is why:

Beach sand is mostly quartz

Desert dunes are mostly quartz

Mature river sediments are quartz-rich

Quartz grains survive multiple erosion–transport cycles

Quartz is the mineral equivalent of a cast‑iron pan: simple, tough, and nearly indestructible.

🪨 Quartz in sedimentary rocks

Quartz shows up in several forms:

1. Quartz grains in sandstone

The chapter notes that quartz is the most common sediment grain because of its hardness and chemical resistance.

2. Chert

A microcrystalline form of quartz that precipitates from silica-rich groundwater.

3. Siliceous ooze → chert

Biogenic silica from diatoms and radiolarians accumulates on the deep ocean floor and lithifies into chert.

🔬 Quartz in igneous rocks

Quartz crystallizes at low temperatures (~700°C), which is why it appears in:

Granite

Rhyolite

Pegmatites

This low-temperature stability is exactly why it resists weathering at Earth’s surface — it’s already close to equilibrium.

🧭 Quartz as a provenance tool

Your chapter mentions zircon as the classic provenance mineral, but quartz also helps reconstruct sediment history because:

It survives long transport

It rounds slowly

It accumulates in high‑maturity environments

A quartz‑rich sandstone (quartz arenite) tells you the sediment has been recycled many times.

🧩 The simplest summary

Quartz is the endurance athlete of minerals:

Hard (Mohs 7)

Chemically resistant

Common

Survives weathering

Dominates mature sediments

If feldspar is the mineral that changes, quartz is the mineral that persists.

If you want, we can go deeper into:

Why Si–O bonds are so strong

How quartz transitions into chert

How to identify quartz in hand sample

Why quartz-rich sands dominate Earth’s deserts

Just tell me where you want to take it next.