South from the landing site, sols 72-237, Starting the science traverse Options

[Guest_Actionman_*]

The Rock it's self has a dark dark gray blue thin veneer as do just some of the crystals inside, and some of the crystals (drill area) look to have an iron coating which would be more then likely a iron stain.
This rock seems to have dust adhering to it where there are other rock along the way that are blue color that are dust free and very very shiny.

[tau]

As for the "blue rocks": in reality they are rather gray. If there are blue rocks in my processed images, the blue is due to image processing designed to enhance the hue differences in the raw images,
and in some cases (especially the SuperCam RMI images) simply because I don't have a calibration for white balance and therefore use other SuperCam RMI images for flatfield and white balance.

Below is an example of a Mascam Z image of sol 145 with a part of the original image on the left. One method of increasing hue differences is to increase saturation.
The result is the displeasing image in the center with greatly exaggerated yellow-orange. To avoid this strong color cast, all RGB values can first be shifted
from yellow-orange toward the gray axis in the color space. Original RGB values that were gray or at least less saturated inevitably move into the blue range
and become even bluer by increasing the saturation. This is the reason for the "false-color blue" rocks in the right processed image.
My methods are more complicated, but the priciple is similar to the one described above.

[Bill Harris]

As for the "blue rocks": in reality they are rather gray. If there are blue rocks in my processed images, the blue is due to image processing designed to enhance the hue differences in the raw images...
SNIP

Years ago we started to enhance color differences while minimizing the "Orange Overcast" present in the images from Opportunity and Spirit. This was done as Geologists to spot gross compositional differences in subtle color differences. Your processing technique shows close to the same thing we did.
This blue suggests a basaltic composition.

--Bill

[tau]

Here comes some more false-color blue. In reality it might be a gray, probably with a subtle green tint.

Abraded rock on sol 207.
1) Sherloc Watson camera raw image, enhanced with principal components analysis.
2) Merged overlay of Sherloc Autofocus and Context Imager raw image (brightness and detail) and no. 1 (hue and saturation).
1
2

[Bill Harris]

Abraded rock on sol 207.

2) Merged overlay of Sherloc Autofocus and Context Imager raw image (brightness and detail) and no. 1 (hue and saturation).
2

I like this "merged overlay" processing; it shows the glint (luster) of the abraded (fractured) mineral grains very well after the "dust blower" cleans up after abrasion.
This is a very informative view: it suggests a look at the mineralogy of this specimen, and further suggests that it appears to be well-indurated (cemented) and even suggests some weathering between the grains. It would be interesting to learn the drilling pressure on the core sample.
Indeed, there is a lot going on in this image! Thanks for sharing it, Tau.

--Bill

[serpens]

and yet, Ingenuity photographs many rocks that are blue in color.

Are you talking about Tau's enhanced versions of Ingenuities images? Basalt is generally grey to black in colour but some crushed basalt has a blue black appearance which gave rise to the term blue metal as road base. But perhaps a visual example is the best way to explain it to you. In Tau's copied image below the false colour image is merged with the mastcam 'real colour' image. As you can see the rock is not blue and the false colour image could best be described as dark grey. The same is true of Ingenuities images. The enhanced, false colour images are not 'real'.

Attached thumbnail(s)

 

[serpens]

The outcrops in that image look grey to me but I do note the horizon at the top right shows a grey blue sky. Ingenuity color camera images vary between near grey scale and full color and I assume this is a function of the Bayer color filter array. The outcrops are not blue. With respect to the SHERLOCK context image the acronym, stands for Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals. The images are taken under ultra violet illumination.

[mcaplinger]

There is nothing wrong with Mars Helicopter Color Camera. (that I know of)...
Crystalline is a very general term, highly reflective would be closer to describing what they look like. All of it is.

The color balance of this COTS camera has been quite unpredictable if you go back and look at all of the images. Having said that, are these rocks "bluish" by some metric, sure, wouldn't surprise me.

As for the shiny rock, I've taken images of regular old quartz-bearing rocks in the lab with MAHLI that looked just like this image, you don't have to resort to an unlikely hypothesis involving water to explain it.

[Bill Harris]

And one item added to the toolkit on the Arm is the GDRT (dust removal tool) which seems to do an exemplary job of removing the residual dust from the abrasion process. I don't have a feel for how this camera shows the various degrees of luster, but I believe that I'm seeing a vitreous luster.

[djellison]

Thought they would have used the laser by now.

Based on SuperCAM RMI pictures - they have.

[atomoid]

Thanks djellison for posting that link, I hadn't come across that page yet and love the Enhanced/Natural color toggle button below the images
https://mastcamz.asu.edu/mars-images/images...al-color-images

I've been flummoxed by the radial pattern, as as can be seen in this example reference earlier by Tau. I was losing too many synapses wrestling with the impossibility of radial abrasion, so perhaps the pattern is simply composed of remnant dust left over from the GDRT process?
I haven't kept up with this mission as well as i'd like so this tool is new to me and of course am firstly concerned about how many uses the nitrogen tank can supply.

[PaulH51]

.....how many uses the nitrogen tank can supply.

The gDRT is sized for a minimum of 888 nominal puffs. For an average abrasion consuming 3-4 puffs of 1 second duration for dust removal, this provides a 3-4 times factor of margin over the required 74 minimum abrasions.

I believe this is the link but it's paywalled

[PaulH51]

Drive on Sol 210 (site: 7, drive 2050)
L-Navcam mosaic of 4 frames roughly tiled in MS-ICE (de-greened)

[Bill Harris]

The Ingenuity color camera is an off-the-shelf Sony IMX214 camera module, which can be googled.

--Bill

[mcaplinger]

The Ingenuity color camera is an off-the-shelf Sony IMX214 camera module, which can be googled.

When you find something about how the auto white balance works under martian conditions, please send a link.