Finding and collecting earth pigments can be both exciting and rewarding endeavor. Collecting pigments from the earth is something that can be done causally as you drive through the country, or with much planning and preparation to identify and collect specific mineral pigment types. This is the first article in a series on finding, collecting and preparing your own earth pigments.

A few years ago, I stopped along Highway 80 in the Sierra Nevada Mountains of California, about an hour west of Lake Tahoe. Recent road construction had scarred the earth next to the highway, revealing a deep blood-like orange beauty. Not often leaving my car so close to speeding traffic on an interstate highway, I opened the car door with excitement and some trepidation. As if taking my own life in my hands, I grabbed a trowel and bag from the trunk and ventured off the road to scoop up the bright orange soil.

Fig. 1. Brush out in egg tempera of soil gathered off of I-80 west of Lake Tahoe, California, USA.

The soil I collected was beautiful in itself and after washing, it produced a transparent golden orange with yellow undertones that was stunning (fig. 1). I used this pigment in the icon painting of the Korsun Mother of God (fig. 2) as the roskrish, or base coat, under the linear gold on the Christ child's garment and on the bands of the Mother of Gods under garment. These were good places to use this pigment and the gold stands out well against this background color.

Korsun Mother of God

Fig. 2. Earth colors were used in the base coat of the icon of the Korsun Mother of God, egg tempera on wood panel by author.

In the following year, I collected soil just west of Albany in southwestern Georgia, USA. This time the soil was a rich red-orange and the pigment it produced could be described as transparent bright orange-red with deep red undertones (Figure 3). I have not used this pigment in iconography yet, but it seems well suited to floats on garments over darker under coats. It also might be suitable under linear gold as a substitute for the Mexico Dark I use, a pigment no longer carried by Kremer Pigments, though this Georgia earth pigment is brighter and has more red than Mexico Dark.

Fig. 3. Brush out in egg tempera of soil gathered west of Albany, Georgia, USA.

Collecting Colored Earths

To begin collecting pigments you must open your eyes and develop a consciousness of the color of the earth around you. Examine soil in any exposed area not covered by plants or pavement. Once you are aware of the variety of colors in soils around you, you can begin to find deposits of colors that are pleasing to you.

Choose deposits that are free as possible of rocks, sand and organic material. An open field where plants are cultivated or an area of dense growth is not a suitable place for collecting pigments from exposed soil. Sandy areas, especially near coasts are not likely to contain intensely colored soils. Look for good specimens in such places as quarries, road cuts, eroded areas, the banks of rivers and construction sites where access to colored earths are relatively free from organic matter and other contaminates.

Once you have located a deposit, collecting samples is quite simple. Always be prepared with a tool for digging, such as a garden trowel or small shovel and a container to hold the earth for you can unexpectedly find colors. I always carry a trowel and a supply of 1-quart Ziploc plastic bags in the trunk of my car for those moments.

Making Notes of Your Collections

Any artist who collects and uses earth pigments is advised to keep very good records. Without good records it is difficult to repeat desirable results and to avoid repeating less desirable ones.

The first thing that should be recorded about native earth pigments is where and when they were collected. The place description should be descriptive enough so that you could return to a site to get more of a pigment. This information might be placed on the label on the container of pigment. Below is an example of how you might set up a notebook for detailed record keeping of your pigment making processes and results. You can use this example to develop your own notebook for sample collection and pigment documentation.

NAME Auburn Orange Ochre
WHERE FOUND Road cut about 45 miles west of Lake Tahoe in the Sierra Nevada Mountains, California, 2 miles east of Auburn, 50 feet from Highway I-80
DATE September, 2000

A loose leaf binder, with sheets that can be removed or added easily, makes an excellent notebook for data on earth pigments. Below are other notes that should be made to complete your notebook.

Location

  • Name of general location, such as highway, road or park
  • Note nearby highway exits, cross streets, towns or cities.
  • Was collected from side of a road? Name the road or highway and add compass directions, such as north, south, east or west.
  • Describe conditions at the collection site.
  • Was the sample collected from the surface of an exposed area?
  • Did you turn the soil to collect the sample?

Date

  • Give the date when soil was collected.

Characteristics

  • Is the sample gritty? Clayey? Powdery?
  • What is the color of the sample? Compare it with other known pigments or pigments in your collection, such as French Gold Ochre.

Pigment Evaluation

You will want to also include color swatches made from the earth pigment in the paint medium you intend to use it. In future articles in this series we will describe how to make these tests or perform these evaluations.

  • Tinting strength
  • Hiding power
  • Grades: Particle size at various stages in the grinding process
  • Lightfastness tests
  • Color mixture tests

Process Evaluation

  • How was the collected sample prepared?
  • Was the sample easy or difficult to prepare?

General Evaluation

  • Is this pigment worth the effort?
  • Do you want more of this earth color?
  • Where will this pigment be useful? (Painters might note what elements of an icon are best suited for this pigment, i.e., mountains, garments, flesh, or whatever part of the icon for which you think it is suited.)

Identifying Colored Earths

You can identify earth pigments visually. You will be attracted to certain soils because of the intensity of its color. But do not let your perceptions of the soil in its environment mislead you. A red earth may appear to be an intense hue when surrounded by its complimentary green foliage, but back in the studio it may appear to be lifeless and dull. A color is affected by colors adjacent to it, so evaluate the colored earth immediately by placing a small sample on white paper in indirect sunlight. Wet soil will appear more intense and darker than dry soil. The time of day and quality of light, such as an overcast day or bright sunlight, will also affect your perception of colors.

A soil that appears intense chromatically may not have the same intensity when ground and mixed in a paint medium. The pigment may also lack the tinting strength and hiding power needed to make it effective for your palette. Soils may contain a high proportion of kaolin, silica or clay and be quite translucent and weak when mixed with a medium. In oil medium these substances are usually translucent, whereas in egg tempera or watercolors they may be more opaque. Other natural minerals, gypsum, talc, marble dust, alumina hydrate, magnesium carbonate, barites--all have similar properties and are classified as inert pigments. These materials are added to paints as fillers to extend pigment and in some cases add body to a paint.

Once you have collected and identified your sample, you are ready to prepare the soil for use as a pigment. The process is quite simple and will be described in the next article of this series.


Written by Nancy Jackson, Timshel Studio, www.timshelstudio.com