Turquoise Matrix Explained: Spiderweb, Waterweb, Picture Rock, and Low-Grade
Matrix is the host rock that remains visible within a finished turquoise stone. Four types are recognized: spiderweb (rarest, evenly distributed veining), waterweb (lighter or spherical host rock), picture rock (pattern resembling a recognizable shape), and low-grade (host rock dominates over turquoise). Named mines like Number Eight and Lander Blue are prized specifically for their matrix character.
Mateo's Field Notes
Lowry provides the four-type taxonomy in precise terms. On spiderweb: "SPIDERWEB OR EGGSHELL — the rarest matrix; these formations occur when the host rock forms an evenly placed pattern within the turquoise formation." Waterweb: "WATERWEB — a light web, lighter host rock or darker spheres." Picture rock: "PICTURE ROCK — pattern resembles a shape." Low-grade: "LOW-GRADE — host rock dominates over stone." These are not casual descriptors — they correspond directly to value tiers, with spiderweb commanding the highest premium and low-grade the lowest.
A 1908 trade catalog entry preserved by Chambless shows that matrix turquoise was already understood as a distinct category with premium appeal at the height of the Great American Turquoise Rush: "The matrix turquoise is the most popular on account of the beautiful marking. The stones are like beautiful dream pictures and no two are alike." (Southwest Turquoise Company catalog, 1908.) That same catalog identified an even rarer variant: "The 'cobweb turquoise' surpasses all other in its beautiful markings. This is very rare as there is only one mine which has this particular quality." "Cobweb turquoise" is the period term for what the modern market calls spiderweb.
Specific mines validate the taxonomy. Lowry on Number Eight: "what is considered to be some of the best golden and black spiderweb matrix turquoise in the world." On Lander Blue: "quality grade of color and spiderweb matrix." (p. 224.) When buyers pay a premium for Lander Blue or Number Eight material, they are paying in significant part for the matrix pattern — not just the stone color.
Collector's Handbook
- Rarity order. Spiderweb > waterweb > picture rock > low-grade, by both rarity and market value. An even, uniform spiderweb with fine veining commands a premium at every price point.
- What makes spiderweb "even." The host rock veins should be consistently distributed across the stone — not clumped on one side or running in a single dominant channel. Evenness of pattern = spiderweb; irregularity = more likely picture rock or low-grade.
- Matrix color matters too. Number Eight's golden matrix is itself a value factor; Bisbee's dark brown or black matrix against deep blue is another. Ask which mine produced the matrix, not just the turquoise.
- Period vocabulary. If you encounter pre-1950s catalog or appraisal language, "cobweb turquoise" is the historical term for spiderweb. The terminology is the same material category.
- Low-grade is not "bad." Low-grade matrix stones can be beautiful and appropriate for certain jewelry designs. The collector caution is price: low-grade should not be priced as spiderweb, regardless of how attractive the individual stone looks.
Related Entries in the Directory
Browse artists working with named-mine spiderweb material in the Silversmith Directory. For mine-specific profiles, see related entries below.
Primary Sources
- Lowry, Joe Dan & Joe P. Lowry. Turquoise: The World Story of a Fascinating Gemstone. Gibbs Smith, 2010, p. 224 (Lander Blue matrix).
- Chambless, Philip & Mike Ryan II. Turquoise in America, Part One: The Great American Turquoise Rush 1890–1910. Callais Press, 2021.