Aragonite question

What is the difference between aragonite, calcite and dolomite?

I have found reference to the difference in buffering capabilities, but
what is the difference as far as actual composition?

Thanks,
Mark

On 15 Mar 2006 17:37:49 GMT, Mark Cooper wrote:

What is the difference between aragonite, calcite and dolomite?

I have found reference to the difference in buffering capabilities, but
what is the difference as far as actual composition?

Thanks,
Mark


Aragonite
a mineral consisting of CaCO3. Aragonite is less stable than
calcite under pressures at the surface of the Earth. Calcite
precipitation is often inhibited, however, and both modern and ancient
seawater are supersaturated with respect to calcite. With high enough
supersaturations, aragonite can also precipitate. Aragonite is common
in many modern carbonate sediments.

Calcite
a mineral consisting of CaCO3. Sometimes Mg2+ substitutes for Ca2+
forming Mg-calcite.

Dolomite
carbonate mineral consisting of MgCa(CO3)2. It is the most stable
carbonate mineral in the oceans, but it precipitates very slowly.
"Dolomite" also refers to rock consisting of mostly of the mineral
dolomite.


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to add Aragonite is a little more soluble that calcite. Aragonite is just another morph of
CaCO3

In Aragonite Ca is often substituted for Sr, Strontium but unlike Aragonite Sr it will
not fit into a Calcite crystal lattice, as it is to big. Most carbonates in the ocean to
include corals and shells are aragonite or aragonite based.

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Comatose wrote in message ...
: On 15 Mar 2006 17:37:49 GMT, Mark Cooper wrote:
:
: What is the difference between aragonite, calcite and dolomite?
:
: I have found reference to the difference in buffering capabilities, but
: what is the difference as far as actual composition?
:
: Thanks,
: Mark
:
:
: Aragonite
: a mineral consisting of CaCO3. Aragonite is less stable than
: calcite under pressures at the surface of the Earth. Calcite
: precipitation is often inhibited, however, and both modern and ancient
: seawater are supersaturated with respect to calcite. With high enough
: supersaturations, aragonite can also precipitate. Aragonite is common
: in many modern carbonate sediments.
:
: Calcite
: a mineral consisting of CaCO3. Sometimes Mg2+ substitutes for Ca2+
: forming Mg-calcite.
:
: Dolomite
: carbonate mineral consisting of MgCa(CO3)2. It is the most stable
: carbonate mineral in the oceans, but it precipitates very slowly.
: "Dolomite" also refers to rock consisting of mostly of the mineral
: dolomite.
:
:
: ================================================== ===
: Join our growing group of reef fanatics.
: New Aquarium forum=== http://coszam.net/forum
: ================================================== ===

Years ago crushed dolomite gravel was *the* thing to put
in the bottom of the tank. It was later realized that it
does not disolve and buffer the water as well. Now it
would be rare for any decent store to even stock the
dolomite. Works good in the driveway though :-)

Wayne Sallee
Wayne's Pets



Mark Cooper wrote on 3/15/2006 12:37 PM:
What is the difference between aragonite, calcite and dolomite?

I have found reference to the difference in buffering capabilities, but
what is the difference as far as actual composition?

Thanks,
Mark

Wayne Sallee wrote:

Works good in the driveway though :-)


Why would I want a fish tank in my driveway....?

;-)

mark h - Is it Friday yet?

"Mark Henry" wrote in message
m...
Wayne Sallee wrote:

Works good in the driveway though :-)


Why would I want a fish tank in my driveway....?

MTS ...Its for when you run out of room inside the house.

DaveZ
Atom Weaver

Now that would be cool. Have a *big* arch tank over the
drive way, in the yard, that you would drive through to
get to the house :-)

Wayne Sallee
Wayne's Pets



David Zopf wrote on 3/17/2006 9:30 AM:
"Mark Henry" wrote in message
m...
Wayne Sallee wrote:
Works good in the driveway though :-)

Why would I want a fish tank in my driveway....?

MTS ...Its for when you run out of room inside the house.

DaveZ
Atom Weaver

LOL
Down here it's common to have an Oyster Shell Drives.....
Soooo every time it rains you got a biosphere, think of it as a tidal
pool :-)

Mark Henry wrote:

Wayne Sallee wrote:


Works good in the driveway though :-)


Why would I want a fish tank in my driveway....?

;-)

mark h - Is it Friday yet?


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Wayne Sallee wrote:
Now that would be cool. Have a *big* arch tank over the drive way, in
the yard, that you would drive through to get to the house :-)

Yeah, but the heating cost would kill you here in New Jersey.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

Yea, but I live in Central Florida :-)

Wayne Sallee
Wayne's Pets



George Patterson wrote on 3/17/2006 10:02 PM:
Wayne Sallee wrote:
Now that would be cool. Have a *big* arch tank over the drive way, in
the yard, that you would drive through to get to the house :-)

Yeah, but the heating cost would kill you here in New Jersey.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.