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." (~line 9405–9470.) 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, ~line 9903.) 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." (~line 9906–9908.) "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." (~line 11391–11393.) On Lander Blue: "quality grade of color and spiderweb matrix." (~line 11723–11725.) 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, ~line 9405–9470 (four matrix types); ~line 11391–11393 (Number Eight spiderweb); ~line 11723–11725 (Lander Blue matrix).
- Chambless, Philip & Mike Ryan II. Turquoise in America, Part One: The Great American Turquoise Rush 1890–1910. Callais Press, 2021, ~line 9903 (Southwest Turquoise Co. catalog 1908, matrix popularity); ~line 9906–9908 (cobweb turquoise, period term).