Geoscience Reference
In-Depth Information
Ikornikova (1970)
[192]
has obtained transparent crystals of FeCO
3
in NH
4
Cl solu-
tions at T
5
350
C, P
5
300 atm.
CaCO
3
(spherocobaltite). The growth of spherocobaltite crystals has been car-
ried out on the seeds in the LiCl solution. Autoclaves of 300 cm
3
using titanium
liners have been used. Separate experiments have been carried out in 1.2
300
600
800 atm, and P
CO2
5
1.7 l
autoclaves with platinum liners. Spontaneously grown crystal was used as a seed
crystal. However, detailed studies on the growth of spherocobaltite are not known
[191,192]
.
CdCO
3
(otavit). Monocrystals of otavit were first obtained by Ikornikova
[192]
.
Crystals were grown in LiCl (5
20%) and NH
4
Cl (1
5%) solutions in the temper-
550
C,
20
, P
ature interval 300
900 atm. The size and quality
of the crystals in the growth zone were regulated through the concentration of solu-
tion and temperature gradient.
NiCO
3
. Monocrystals
Δ
T
15
700
5
5
of
carbonate
of
nickel
could
be
obtained
at
500
C and P
T
1500 atm using NiCO
3
, Ni(OH)
2
. During the evolution of
CO
2
in the autoclave, the crystallization of NiCO
3
takes place at a much lower
pressure and in a NH
4
Cl (2
150
.
.
10%) solution
[178]
.
5.57
show photographs of some selected hydrothermally synthe-
sized carbonates in the hydrothermal laboratory of Byrappa.
The growth of carbonates, in general, is quite interesting academically, techno-
logically, and geologically.
Figures 5.55
Figure 5.55 ZnCO
3
crystal.
