Identify the material of the rug.The Navajo people were introduced to wool cultivation during the 17th century Spanish settlements. A majority of authentic Navajo rugs are made from hand-spun wool threads, with the exception of a small amount of 19th century rugs made from US-government supplied cotton.
Identify the type of weave in the rug by following the weft, or horizontal, threads across the rug. Standard American colonial weaving involves carrying a single color of thread across the entire rug before reversing direction to create the weave. Navajo textiles do not carry a single color all the way across a rug unless the color pattern calls for it. The Navajo employ a discontinuous weft style in which the color reverses direction wherever the block of color ends.
Look for a toothed pattern where two blocks of color meet. The discontinuous weft pattern requires weavers to link two different colors in a rug pattern with a small knot. The knot causes the threads to pull, creating a jagged edge around interlocking color blocks.
Investigate the ends of the rug for fringe. A majority of authentic Navajo rugs do not have fringe because the bottom beams of Navajo looms are wrapped with a single piece of yarn that creates a flush edge. A small percentage of authentic Navajo rugs have fringe added after the rug is done, so contact the seller to inquire about the addition of fringe if your rug has fringed edges.
Look for a single thread that lines the vertical edges of the rug. Selvage cords help Navajo weavers keep a straight edge, and the presence of a single-thread border around your rug supports authenticity.
Identify the rug pattern. The oldest Classical Navajo rugs include simple patterns of repeated broad and thin stripes. Rugs from the mid-Classical period introduced rectangular blocks of colored stripes, and late-Classical rugs have diamond or checkerboard patterns. Transitional period rugs from the late 19th century include distinctive patterns created from several small diamonds, and 20th-century rugs typically include a large central pattern and simple border.
Identify images. Arrows, animals, crops, mountains and landscapes are the most common motifs, and the style remains largely geometric rather than realistic. Pictorial images on a Navajo rug indicate a rug made after World War II.
Examine colors. The oldest Navajo rugs from the Classical period included hand-dyed threads in white, cream, brown and black colors. Red and blue threads indicate a rug made after 1760. Greater color variation typically indicates a later-period rug.