Cutting Capistrano: Making the CNC keystone cut.

Jeffrey Appling GJG (GIA)

I was recently collecting Nephrite Jade and Snowflake Obsidian along a gem filled strata in San Simeon, CA.

Digging or collecting anywhere in Nature is one of my meditations.

Below is Nephite, Jade from San Simeon California.

A portion of the Nephrite Jade easily broke off showing iron staining over its already weakened and exposed fracture.

From this Nephrite, Jade boulder I can make simple sculptures using a diamond saw and sonic technology (ultrasonic carving/coring).  One side shows iron oxide over the Jades step-like fracture and the opposite side shows machine engineering.

These California Jade sculptures make great jewelry stands for “Jewelry of the Gods”

One of the stones I came across in San Simeon had geometric looking indentations. A possible dissolving of another mineral within a mineral.

I know from my Gemology training that sometimes a mineral within a host mineral can dissolve out leaving behind its crystal form as a geometric void as shown below.

(Above) is a photomicrograph by Peter Vollenweider.

The anhydrite crystal is dissolved out of its Quartz crystal host leaving a near perfect geometric cavity.

Nature does not make perfect geometrics in stone.

Handheld chisels do not make perfect geometrics in stone.

(Below) A steel chisel can quickly make a square indentation in wood.

A steel chisel can easily make uneven indentations in softer rocks like Sandstone (pictured below), Limestone, and Volcanic Tuff.

It would take great mastery to make perfect step cuts at 90 degrees with a Chisel. Human error in hammering can deviate from make clean lines.

Scalloped steel chisels can carve out Limestone fairly quickly but leaves corrugations which are hard to clean up.

(above) A scalloped chisel carved out this 400-million-year-old Orthoceras fossil (7-foot cone) from Limestone.

No hammer blow with a steel chisel can perfectly execute the below Volcanic Tuff keystone block.       

To test how it would be completed today I had my friend Gary use his expensive CNC machine and software to execute the work. He uses a high-speed spinning carbide drill bit that is guided by computer software.

I gave Gary just a picture of the keystone block and he spent hours figuring out the high and low relief dimensions via computer software.

Gary machined the keystone design into a semi hard 12” x 9” x 3” foam block similar to Volcanic Tuff.  The actual carved Keystone is a trapezoid cut over 12” deep. Not achievable by a steel chisel.

Sandstone contains quartz which can wear down the carbide spinning tool, so for my upcoming documentary I will use Volcanic Tuff from California.

The floral carving is perfectly symmetrical.

So, what’s up with the different numbered curved indentations around the perfect center flower?

Left side row of 5, bottom row of 3, and right-side row of 4.

If anyone wants to help me a decipher the Capistrano codes, symbols, and numbered patterns I want to hear from you!

I’m tired of being Rogue One!

2 thoughts on “Cutting Capistrano: Making the CNC keystone cut.

  1. Could have the significance of being the first Pythagorean Triple. Would you be interested in making a zoom presentation to the South Orange County Gem and Mineral Society? We would like to hear about your sonic jewelry designs and the “secrets” of the San Juan Capistrano Mission.


    1. The Pythagorean triple is a possibility. Yes, I would be very interested in a zoom presentation discussing sonic drilling with minerals. I’m a rock hound first and always so this will be a great platform to share earth science, Lapidary (stone construction), and of course secrets of Capistrano.
      Thanks for reaching out and talk soon.


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