" George" wrote
It has been my understanding from reading the interviews of the project
scientists that they were referred to as blueberries because of their
shape
and size, not because of their color.

Mark Lemmon: "We've looked at the floor of the crater itself and it's
exciting. In particular, this area is covered by finescale sandgrains and
these irregular grains coming down from the outcrop potentially and the most
spectacular are these rounded spherules being called blueberries because
they're relatively bluer than their surroundings." (Thursday, Feb. 12)

If you miss them, a lot of the press conferences are archived on C-SPAN;
unfortunately they don't have that one though.

In addition, there is no way that you
can look at the picture you posted above and say that the blue color is
due
to the spherules simply because you cannot even see then at that
resolution.

But you can see the blue color at that resolution, which the blueberries are
in such an RGB composite (with overemphasized blue).


On the other hand, you can look at this image and get a clearer view of
the
color of the spherules.

http://www.jpl.nasa.gov/mer2004/rove...atural-med.jpg

Officially they are calling the color of the spherules "gray." Or at least
grayer than the matrix. Gray hematite anyone?

Here is a link to the TES data collected by the rover:

http://www.jpl.nasa.gov/mer2004/rove..._strip-med.jpg

The data is superimposed onto the panorama of the outcrop and edge of the
crater. If you will note that in the center of the image is the area of
the
outcrop first examined by the rover. That area had a lot of spherules on
the ground around the outcrop (the outcrop referred to as "stone
mountain"),
within the outcrop itself, and below and above it. Note that this area is
hematite-poor. And the outcrop itself was hematite-poor. For
verification,
please note this image of the area I'm referring to:


http://www.jpl.nasa.gov/mer2004/rove...ontext-med.jpg


http://marsrovers.jpl.nasa.gov/galle...treach1_br.jpg

However, speaking of resolution, this is the area of the "hematite strip"
you are basing your conslusion on:
http://www.copperas.com/astro/hemstrip.jpg

The approximate area of your Stone Mountain closeup is indicated.

You should also note that there are very few images sent back by
opportunity
of the soil in which the spherules were not present, yet there are large
areas that appear to be hematite-poor.

Not really, outside the airbag bouncemarks:
http://www.copperas.com/astro/hematite.jpg

As I've said before, I think is it
too early to say that the spherules are composed of hematite. Looking at
data brought back from Apollo 14, similar granular spherules were found at
that site that turned out to be composed largely of plagioclase. I think
I
will wait for more data before reaching a firm conclusion regarding the
spherules.

Similar? They were over ten times smaller than these and were made of dark
glass!

Well, we can all speculate all we want to, but my experience with
speculation is this: Don't assume, that way you won't make a fool out of
you and me! :-))

But is speculation, particularly based on current data, equivalent to
assumption?

Joe