Monday, February 1, 2016

A Pebble Mosaic at La Calera, Oaxaca, Mexico

An opportunity to create a sand set pebble mosaic in Oaxaca, Mexico
I've been traveling in Mexico this winter (2015-16) for 3 wonderful months, rediscovering the beauty of this amazing country.  I first came to Oaxaca 31 years ago when I was 26 years old, honing my skills as a traveler.  This is my 33rd winter away and I've learned a lot along the way.  I would expect myself to be jaded by now, returning to the country where the international adventures began for me, but I am continuously blown away daily by how incredible this country south of the border to the United States really is.  The landscapes are biologically rich and diverse, and the culture of the people is equally impressive.  There is far more to Mexico than Puerta Vallarta and Cancun.

A beautifully turquoise mosaiced Mexica skull from the 14th Century
Mexico's history makes the United States look comparitively modern.  There are more UNESCO World Heritage Sites here than in any other country in the Americas, and Mexico ranks 6th in the world for the number of sites as well.  You can see a list of the sites at

A cobble mosaic courtyard in the Centro Cultural Santo Domingo, Oaxaca
One of the most significant of the World Heritage listings is the Valley of Oaxaca, in southern Mexico.    The region is inhabited by a large number of distinct indiginous cultures who still speak their native languages and dress indicitively.  Squash seeds radiocarbon dated to be 10,000 years old were found in the valley, the oldest known cultivated agricultural plants in the Americas.  Major archeological sites such as Monte Alban, Mitla, and Yagul show how impressive pre Hispanic civilizations in the valley became.

Monte Alban
With the conquest of the New World, the Spanish laid out the new town of Oaxaca around the city's Zocalo, or main town plaza in 1529 and it rapidly grew to be the most important town in southern Mexico.  Today Oaxaca is one of the most appealing historic cities in Mexico and is a major center for tourism.  It is known for its beautiful architecture, diverse culture, artisanal crafts, and delicious cuisine.

The Cathedral on the Zocalo of Oaxaca on a Sunday afternoon
When I came here 31 years ago I was intoxicated by the writings of Carlos Castaneda, a controversial apprentice to a Yaqui shaman named Don Juan.  Much of his writings took place in Oaxaca and I was entranced by the idea of being in the Zocalo wondering where he might have sat while struggling with the challenges of becoming a sorcerer.  Whether or not the writings are technically true, I found thier substance to be profound and their influence has been something of a guide in my life and work.

The bandstand in Oaxaca's Zocalo
When I was planning the loose structure of where I might go on this trip, I went to the Airbnb site and found a beautiful modern studio apartment located in a refurbished limestone kiln factory outside the city center and booked it for two weeks without really knowing anything about the place.  When I arrived in the city I hired a taxi driver to take me there, even though he had no idea where it was.  Fortunately for us I had seen a small sign from the highway coming in to town for La Calera, the name of the complex, and we were able to stop and ask people along the way for directions.  I was dropped in a rather unimpressive location, at a yellow metal gate next to a weedy hill with a rough dirt road crossing it.  I was tired from the long bus ride and had to drag my bags past a few rather disconcerting shallow graves lined with rocks to another gate a quarter of a mile away.  It turns out there is a cemetery on the other side of the wall and apparently people who couldnt afford a plot just dug graves in the field.  I walk past these graves every day coming and going, which causes a feeling of introspection and humility.

Simple burials in a field by La Calera, ringed with stones
I wasn't in the best of moods when I passed in to the compound that would be my home for the next two weeks.  Travel is not always that glamorous.  But as fate would have it I had landed in a very special place.

The studio where I stayed sits on top of the white building
The apartment is a simple cube with a wall of glass facing a sleek modern mahogany deck screened in for privacy by rust colored steel containers planted with New Zealand Flax and a steel screen wall.

The Studio apartment I've been staying in at La Calera.  The planters are recycled molds for freezing blocks at an ice factory
The flight of metal stairs leading to the studio
 Luis, the owner told me that the design to support these stairs was inspired by the dried exoskeleton of a crab that his grandson found on the beach at Huatulco when his family was on vacation.  The man who does his welding projects took the concept and created the structure for the stairs in square tubular steel.

The sun deck 
The awning overhead is an ingenious canopy of panels that can be opened and closed by pulling on rope levers.  Once I got settled in and adjusted to the place, which is in a fairly unattractive part of town, it started to grow on me.  La Calera is a facinating institution with a number or residences inhabited mostly by Americans working on a variety of projects in Mexico.

One of a diverse variety of residences at La Calera with the smoke stack on the left
A plan of La Calera
Cal means lime in Spanish.  Lime is an essential ingredient in making cement for construction.  It has been used since ancient times and there are lime kilns all over the world.  The process of making lime requires crushing the rock and a kiln for heating the crushed limestone.  You can read about the process at

A 16th Century Lime Kiln excavated at Santo Domingo in Oaxaca

A hanging melted bottle installation and limestone kiln equipment
 The owner and visionary man behind the project at La Calera is Luis Jesus, a residential developer interested in sustainability, environmental causes and the arts.  He inherited the factory in 2002 from his father, which had been built by his grandfather.  He began to develop what is an ongoing project with no clear plan in the beginning as to what it would become.  A few artists set up workshops in parts of the the compound.

Meeting space

Massive equipment at La Calera
Later his son built a house in one corner of the property, and eventually other bungalows were added.  I was soon meeting an interesting mix of people as I came and went from the complex on my excursions in to the historic center of Oaxaca and out to villages and archeological sites around the valley.   I joined a symposium one day on the preservation of native bee habitats, met a man building Mezcal distilleries, a woman working with a renowned Mexican singer, and a renewable energy consultant.

An artist's installation of a flower bed made of dried marigolds hangs in the kiln building
The industrial site has been ingeniously converted in to a residential and educational compound with a number of well integrated art installations enhancing the massive limestone kiln machinery in the warehouse.

One of a variety of attractive gathering areas
Industrial materials from the factory have been retrofitted in to art and furnishings
Another seating area built inside a huge steel vessel salvaged from another lime factory
The same seating area illuminated at night
A large sprocket as a window
A beautifully composed log round mosaic patio surrounded by an Organ Pipe Cactus fence
There is a nice library for research with a great collection of Luis's books displayed on unusual shelves.  Although the design is whimsical, the shelves will be rebuilt because the angles are not good for the spines of the books.  The hanging installation was created by an artist in residence.

The library at La Calera
Groups of school children regularly come to La Calera on educational field trips
A flatbed trailer is converted in to a deck edged with ice mold planters filled with Organ Pipe Cacti

A variety of spaces in the facility are set up to feature environmental campaigns such as a project for the preservation of native bees.  The stacked boxes were once used to freeze blocks at an ice factory
A collage of scrap metal forms a screen
There are areas mulched in river pebbles, which I habitually checked out to see if they had potential for use to create pebble mosaics.  I had a copy of my self published book, The Gardens of Jeffrey Bale, which I carry as a kind of portfolio, which I showed to Luis.  A couple of days later after finding the shapes of many of the pebbles there to be remarkably flat and perfect for pebble mosaic, I approached Luis with the idea of making a demonstration mosaic inside a round concrete bench around a tree at the base of the stairs to my apartment.  He loved the idea and called two of his workmen who specialize in concrete work, knowing that they would be interested in what I do.  They responded with enthusiasm and within an hour were preparing the site to my specifications.  He is ordering a copy of my book for them to use as a reference.

The pebble mulch area where I collected most of the stones for the mosaic
Since the area I wanted to mosaic was inside a low circular wall, it wouldn't be subject to foot traffic.  To maintain the health of the tree, I wanted to set the pebbles in sand rather than mortar so that the mosaic would be permeable and not affect the health of the root system of the tree.  There are openings at the base of the round wall where the shallow tree roots pass underneath and allow water to drain out. The workers mortared low bricks to the bottom of the holes so that a 4 inch layer of sand could be contained in the tree well.  When I returned from a day trip that evening the site was prepared and I started collecting stones and setting them in the dark, working on the only area illuminated by lighting.

Starting the layout of the stones around the edge
I mix larger stones with narrow ones around the outer edge to create a balanced composition
The stones that I choose are flat on the top and sides so that they fit tightly together, so that there is no horizontal movement.  They are usually at least 2 or more inches (4 1/2 cm) thick so that they can be well imbedded in the sand.

Add caption
One of the reasons I offered to build this mosaic is because there were plenty of nicely shaped stones available to create a beautiful and varied composition.  I like the way the long thin pieces look interspersed with the larger stones.  I left for the day after working for a couple of hours in the morning.  When I returned, the workers at La Calera had gathered stones on their own according to the instructions I had given them.  They did a great job and I was able to use about 3/4ths of what they collected.

Pebbles gathered for me by the workers at La Calera
It can be fun for me to lay the stones when I have nice material to work with.  I've been doing this kind of work for about 25 years and have a good sense of where each stone might fit by quickly analizing its shape and then seeking out the best possible spot for it.  This is a great way to learn how to fit stones together because if it doesn't fit you can always move it.  Unlike mortar, which you have a limited amount of time to work with before it dries, there is no rush working in sand.  But if the stones are not fit tightly together this kind of mosaic will not hold together well over time because they can shift around if disturbed.  I was able to stand on the mosaic without having any of the pebbles move.  This kind of work can also be accomplished by adding some cement to the sand mix, and wetted later to harden it, but then it wouldn't be permeable.  Weeds may also sprout between the rocks, but this is a desert climate so that is less likely to be a problem.

Making progress
I imagine it took about 10 hours to assemble the entire mosaic.  I set the stones all the way up to the edge of the tree, which will over time push or grow over the ones around the trunk.  I used tiny pebbles to fill the smallest holes between the larger stones to give it extra tightness.  This also gives the mosaic a level of detail I find pleasing. Water will be able to drain in to the ground and the tree roots will be able to breathe, which keeps the tree from heaving the work.  I am not invested in permanence with this project.  My main objective was to create an example of how I work so that the guys here can create their own pebble mosaics around the La Calera property for future projects.  It is a great way to create finely finished details in places that need something special.

The completed mosaic
A closer detail showing the small pebbles tucked in to holes
I could easily spend another hour filling the tiniest holes with small thin pebbles.

Another view of the mosaic
I then swept sifted brown sand in to the gaps between the stones to bond them together, and give the mosaic more strength.

Sand swept in between the pebbles finishes the mosaic
A tile I found in the field contrasts with a variety of pebbles selected for their flat tops and square sides
 The mosaic reminds me of cobbles streets that you see in old Mexican cities.

A cobblestone street in Patzcuaro, Mexico
I enjoyed fitting all of the different shapes together on this project
 When I do these long winter trips it is nice to be able to create something in response to all of the inspiring places I have visited.  Hopefully this will in turn inspire the masons at La Calera to create their own pebble mosaics on the property.

Thanks for reading, Jeffrey

The colors of the pebbles darken when wet


  1. I read every post that you write. Have your book too! Just wanted to let you know that I find you and your work very inspiring.

  2. Replies
    1. Beautiful Jeffery> I would love to ask you for a couple suggestions on a large project I am starting shortly.. wondering if you ever allowed yourself to be bothered by the general population?

    2. I'm starting a large project in New Zealand in a few weeks that will span part of the next 4 years so I'm not taking any new work. May I suggest following my Gardens by Jeffrey Bale page on Facebook, or visiting my profile on Houzz, where you can ask questions and I will try to get back to you. Thanks