October 09, 2007

Name That Rock!

You read me correctly! This is going to be the main subject of my Babble edition. We have covered more than 1500 nautical miles of
the Baja in the last 6 months and I can say with accuracy that there are as many rocks and geological formations as there is water. No
kidding! The Baja is one very large land mass of rock, surrounded and covered by smaller rocks of all sizes from boulder size to sand
granules.(I suppose one could argue that the whole earth is built like this but ....) I'm not going to go into  scientific explanations of how
and when they developed or what they're called...I'm asking you to! I have NO IDEA. All I can tell you is that I find them fascinating.
Since we started traveling this area, I've been on a search for the perfect rock. Of course, the perfect rock depends on my needs at the
time, as you can see from 2 of the photos below. Otherwise, I've been spending my time as an  explorer of minerals and GOLD! I
keep  my head down while hiking and swimming, searching for those gems that will make me rich, famous or both. Unfortunately, we
have no identification guides on board so I must guess at what I'm collecting. And I must say that the rocks are so very pretty in
different ways that my collection will soon sink the boat. Therefore, I need some help to sort out the "treasures" from the "eye candy".
I recall that I took Earth Science in Junior High where I learned about these things. But that was a LONG TIME AGO. I regret to say
that my memory on the subject has faded. So, I'm appealing to the students out there, especially those younger ones who love a
challenge and are willing to  help. I've included a small sample and will continue in the future if there is an interest from the crowd.
After all, you won't be graded and I have to trust the answers will be accurate.  So, if you're inclined to help, please email the
responses to: sailsoon06@yahoo.com.  Remember that we don't always have Internet so my response back may take a few weeks. By
the way, I'm fairly certain that I've found no gold! : )
Bridgie's Babble - October 09, 2007
Photos #10 and #11 are the same rock. (When I picked it up to turn it over, I was delighted to see that it had been split in half.  I was sure I'd  be able
to spot some gold veins but nothing doing!) Anyway, look at how pretty this jewel is!
This (almost) perfectly flat rock makes a great tool for
It has a double function, too. Heat it up on the burner
and viola! An instant toaster!
A common Red stone.  Volcanic in origin, loaded with
Iron.  
  
A hand held meat tenderizer without clumsy handles. It
fits perfectly in my palm and takes up no precious
space at all.
Granite cobblestone.  Used in making streets in
ancient times and right down to the 1890’s.
I thought I would take a crack at guessing the
rocks.  This is a rock..Yup you got that right,
clearly a former sand stone which has gone
through Metamorphoses….Ugly compacting
under pressure and heat.  Then the ocean got
a crack at it.  Two layers of material indicate
the darker layer was a silt stone mud stone of
fine particles perhaps millions of years old.
And the lighter colored sand stone..not the
black and brown intrusions on layers, means
that the tides depositing the layers were
sometimes lower or higher over several years,
perhaps thousands of years.  The particles in
rubbing both sides on a hard piece of sand
paper.  It will help you determine the particle
sizes.
It is a metamorphic rock composed of a dark
material perhaps fine clay materials from a
silt deposit…note blue-gray color, and
compressed with an intrusion of Potassium
enriched feldspar that was truly crushed into
something approaching marble. Also the
beach pebbles an rocks show the kind of wear
associated with many years of exposure.  
There are several rocks near with brown
translucent appearance which are
interesting.  Cross between Paleocene and
translucent chert.
Photo #3
This one is really hard to describe.  First it has
black rock, black intrusive colored quartz or
feldspar.  It is hard to read.  The lighter colored
rock is from a series of layers of limestone..very
old and metamorphic.  The quartz were
intrusive, that is filled in between cracks in the
original layers, and eventually became part of a
larger rock formation which eventually broke off
and was washed in with the tide.  If you looked
at the shore line, the beach area, and saw pink
rock formations with white and dark green
materials you would be looking at sever hundred
million years of rock formation.  Despite the
young age of the interior mountains in Mexico
and central America, the coastal plane is older.  
Subduction of the Pacific Plate is pushing up
mountains in Mexico and California, but not the
coastline.  The Pacific plate is sliding under the
continental shelf in a diagonal push along the
San Andreas Fault.  Then other faults, in
Nevada, and the Rocky mountains are the result
of earlier platonic activity. And the faults in
Mexico are still very active.  Volcanic activity is
a sign of that pressure building under the NA
Plate.
Photo #5
Interesting.  You can’t fool me.  That is a
Pizza stain on a perfectly good rock.  Or did
you hit someone with this one from your
sling?  Seriously.. I have no idea what the red
stuff is.  The rest is the black and white of a
quartz enriched granite type rock.  The black
stuff is probably hornsfels or Hornblende.  It
isn’t poisonous….But the red stuff is
interesting.. It might be the last part of a
layer of red stone washed away from the
larger rock
.
Red stone is typical of an Iron rich granite
rock. The red is Iron.  The Quartz appearing
rock looks like quartz, irregular rounded
shapes with poor cleavage, but  like all
rocks, time and pressure along with
exposure to rain and pollution from the air,
and the rock changes.  But the RED Stuff is
pretty much found everywhere including
Connecticut, and northern Maine.  PEI in
Canada, has the deepest red dirt I’ve ever
seen.
Photo #8
I'm getting tired of this.  A rock is a rock is a
rock.
: )
Photo #6
many layers of rock, strata, almost perfectly
aligned.  It is beautiful.  The purple colors
might be any number of chemicals combined
to make the color. The reddish yellow is
iron.  The blue color Beryl like, but it could
be any number of  elements.  What is really
beautiful is the symmetry.  The
hornblende…the dark colored layers and
the quartz laden strata indicate a very old
rock.  Several metamorphic changes, from a
shore or lake bed deposits to going down
into the ocean several miles to be pressured
into a hardened rock, and with some
exceptional heading.  The gloss is really
beautiful.  It would make a great hollowed
out ashtray.  (Bad Joke)
Photo #9
This one is really difficult to identify.  It was really cooked.  High head to create high gloss
crystals.  Did you pick it up?  Was it dense?  It does not look like any of the pebbles around it. A
Tektite is a rock, usually black with some red in it.  Volcanic or some say meteorite in origin.  I’
ve never seen one.  But this looks like someone took some red plastic, from a fire truck, and
covered the rock with it and heated it.  But, the gloss is impressive.  Iron colored and muck like a  
golf ball.  I can’t tell from the picture how big the stone is, but it looks like it’s on a beach with
pebble and stone size material. Did you see any ledges around the area red in color?  Or were you
near a volcanic site?  It really is a beautiful rock.  I wish I could help you more.   You know,
Heavy compared with rocks of similar size? I hope you kept it and I pray it wasn’t radioactive.  
Something dropped from a dead Russian Satellite.
Click to enlarge images
Back to Bridgie's Babble
Next Bridgie's Babble Oct. 19, 2007
Photo #11
WOW!!  This is exciting!  The rock is pink in color on the outside, but dark blue-gray on the inside.  It is most likely a form of CHERT..  Or similar
material.  If you still have the rock, take a hammer and smack it good on the side.  If it breaks out in a conical form, convex on the main rock, concave
on the split peace, it is definitely in that form.  That is metamorphic with direct highly intense heat and pressure changing the stone from
quatz-felspar to something akin to arrow head material.  If it is very hard, it has moved into a dark marble quality.. If you hit it with a hammer and it
takes several good smacks  to break it off, then the rock is very hard.. 7 to 8 on the mole scale with diamonds at the highest level.  I have a few pieces
like this from Nevada.  Sorry no gold.
Photo #10  
Notice the white bands of rock in photo #10.  If the crystals have clearly marked flat sections, so you can actually see them as separate layers, then it’s
really Feldspar.  But, Quartz and Feldspars make up about 60% of the world’s rock minerals.  The reddish complexion of the exterior rock shows how
Iron in the rock, taking on the H2O becomes oxidized.  And, iron in the quartz and feldspar acquire iron in their crystals…Pink and Red Quartz,
Rose Quartz etc reflect this.  Also it helps break down the rock when it gets into salt water..A natural source of chemical intrusion, weakening the
crystals and allowing for predominant Iron to bond.
Photo #10
Photo #11
comments with just these photos to work from. Thanks for all the hard work Jim!         
( Jim's responses are in
red )