Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mechanism of saponite crystallization from a rapidly formed amorphous
  intermediate   Although clays are crucial mineral phases in Earth's weathering engine, it is
unclear how they form in surface environments under (near-)ambient pressures
and temperature. Most synthesis routes, attempting to give insights into the
plausible mechanisms, rely on hydrothermal conditions, yet many geological
studies showed that clays may actually form at moderate temperatures (< 100
deg. C) in most terrestrial settings. Here, we present the mechanism of the
low-temperature (25-95 deg. C) crystallization of a synthetic Mg-clay,
saponite. We describe the pathway at the various sub-stages of the reaction, as
we derived from high-energy X-ray diffraction, infrared spectroscopy and
transmission electron microscopy data. Our results reveal that saponite
crystallizes via a two stage process: 1) a rapid (several minutes)
co-precipitation where ~20% of the available magnesium becomes incorporated
into an aluminosilicate network followed by 2) a much slower crystallization
mechanism (many hours to days) where the remaining magnesium becomes gradually
incorporated into the growing saponite sheet structure.

17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom