W038 / Oregon

Crooked River agatized limb casts

Silica-filled plant mould; distinguish from preserved wood texture

A limb cast can keep a branch’s shape without preserving its wood cells.

← Western Lapidary Materials
Reference photograph pending

What it is

Silica-filled plant mould; distinguish from preserved wood texture

What to look for

Compare branching outline, a cast-like outer boundary and chalcedony interior. Pink color alone does not diagnose a limb cast.

At the cutting bench

Fractures and hollow areas can limit slicing. Keep enough of the exterior to retain the feature that made the cast recognizable.

Under the loupe

Compare silicified wood and unrelated nodules. Shape and internal tissue preservation answer different questions.

Source & collecting access

Regional collecting history is not permission for an individual parcel. Current lawful access is not established here.

Status checked 2026-10-03

The market notebook

No verified realized-price range was established for this entry. Asking prices and sold labels are not interchangeable.

Market researched 2026-10-03

Open the field notes

Formation & evidence

Silica can fill a space left by plant material. A labelled cast should not automatically be described as cell-preserving petrified wood; examine the actual structure.

Collecting & trade context

Institutional and collector labels preserve this familiar Oregon lapidary name. Keep original wrapping and the shape as well as polished slices.

Reading an old label

Preserve the exact name, dates, wrapping and associated pieces. Old-stock age alone does not authenticate a locality or imply exceptional value.

Color comparison limits

Pink, White/Cream/Clear, Brown/Tan

What we know—and what we don’t

Visual resemblance can narrow a comparison. Material identity, locality attribution and documented provenance need separate evidence.

C&C Reference Collection

Authenticated reference photography is still being assembled.

Sources & Further Reading
  1. University of Nebraska–Lincoln historical agate database

    Saved institutional label/bibliography evidence; no image reuse permission inferred.

  2. Oregon thunderegg collector: Agates

    Source-labelled Crooked River limb-cast example; collector interpretation, not a parcel map. Images not cleared.

  3. Ochoco Rockhounding — Recreation.gov

    Agency recreation listing; verify restrictions and closures separately.

Historic locality information is not current collecting permission. For cutting, use suitable dust controls and material-specific safety guidance.