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
placing hot cookware on. That way, we don't burn the table.
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
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.
Photo #1
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 the rock
appear micro-sized…Check by rubbing both
sides on a hard piece of sand paper.  It will help
you determine the particle sizes.
Photo #2
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 other elements. Think of hard
clear or 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
Photo #4
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
Photo #7
I'm getting tired of this.  A rock is a rock is a
: )
Photo #6
You are looking at the top of a rock with
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
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
Uncle Jim responded to the 'Name That Rock' challenge. Here are his amazingly detailed and expert comments with just
these photos to work from. Thanks for all the hard work Jim!        
 ( Jim's responses are in red )