Date: Fri, 19 May 2000 06:51:20 -0400 (EDT) From: "Carl Strohmenger (HSC)" <cstrohme@com1.med.usf.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1587$foo@default> Subject: Re: Sand Types: which best?
I live in central Florida near the Gulf of Maxico. Here we have coastal
dunes composed of a mixture of quartz (silica) sand and calcium carbonate
sand (from shell fragments and oolite grains). When you wash this sand with
fresh water, the salt (mostly sodium chloride) is easily dissolved away and
is removed with the wash water. However, the portion of the remaining sand
that is calcium carbonate will dissolve a bit to leave a slightly alkaline
solution (pH greater than 7). For practical purposes, you cannot wash the
sand with enough freash water to remove this calcium carbonate. The easiest
way to tell if the sand is pure quartz or silica sand is to mix some pure
water with the sand and then measure the pH. If the pH = 7, then you have
quartz sand without contamination by calcium carbonate sand, and you can
use the sand for your cps. If the pH is alkaline, then seek your sand
elsewhere.
On our Florida Gulf beaches, quartz sands are found on the more northern
beaches and a mix of quartz and calcium carbonate sands are found as you
move south along the Gulf coast towards Naples. The ultimate source of our
quartz sands is the granite rock formations in the Appalachian mountains.
The ultimate source of the calcium carbonate sands is (mostly) shells which
have been broken and ground to a coarse or fine particle size and then
deposited on the beach by wave action.
A very thorough reference on ecosystems in Florida is, *Ecosystems of
Florida*, edited by Ronald L. Myers and John J. Ewel. University of Central
Florida Press/Orlando. 1990. ISBN 0-8130-1022-5 in paperback. They discuss
coastal sands on pages 429+.
- Carl
On Fri, 19 May 2000, cp@opus wrote:
>
> >The sharp sand is clean and white, but being
> >from coastal dune deposits, I am concerned about the salt. Should I just
> >wash them myself?
>
> a few years ago I used sand coming from one of our beaches.
> I just washed it a few times and I used it on delicate CPs with excellent
> results. Sea salt dissolves very quickly in water and is not a problem.
>
> Regards
>
> Filippo Tassara
> Genoa, Italy
>
>
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