W005 / Wyoming

Blue Forest petrified wood

Fossil wood with a mineral-filled second story

This is more than wood turned to stone. Blue Forest pieces can preserve the wood, a coating around it and minerals that later filled the spaces between them.

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Cut and polished Blue Forest fossil wood with dark wood texture, blue-gray chalcedony and pale stromatolite crust
Source-labelled Blue Forest fossil wood, Wyoming: a cut and polished comparison surface.

James St. John · CC BY 2.0 · Photograph reproduced without cropping or colour changes.

The source identifies the Blue Forest locality, Wyoming. This comparison image cannot establish the provenance of a visually similar specimen.

Image source and provenance · License

What it is

Eocene fossil wood with silica minerals and, in studied pieces, calcite and mineralized microbial coatings. It is a composite fossil material, not one mineral species.

What to look for

Look for wood texture, layered outer coatings and pale blue-gray chalcedony around or within the piece. Not every specimen is blue. Color alone does not identify the locality or the tree.

At the cutting bench

Inspect wood, coating, open pockets and crystalline fillings separately. They need not behave alike under a cutting or polishing tool. Preserve bark casts and natural surfaces where those carry more information than a polished face would.

Under the loupe

Compare wood anatomy and mineral coatings with documented specimens. Other petrified woods may show blue chalcedony. Identifying a tree species requires more than a decorative slab photo; do not assign “pepperwood” to every piece.

Source & collecting access

UNKNOWN — current parcel ownership, claim status, road access and legal collecting at the specific locality were not verified. BLM’s general personal-use wood rule does not settle those questions or authorize commercial collecting.

Status checked September 2026

The market notebook

Market data insufficient for a reliable range. FossilEra slab #3929 is explicitly marked sold: polished on one face, 6.7 × 4.3 inches and 1/4 inch thick. Its sale price is absent. Prices for related rounds, spheres and limbs are not substitutes for that missing transaction.

Market researched 30 September 2026

Open the field notes

Names, labels & aliases

Blue Forest wood. Eden Valley petrified wood is a broader regional label; it should not automatically be narrowed to Blue Forest.

How it formed

Researchers describe lake water rising over forests, microbial coatings growing around wood, drying and shrinkage, burial, and later silica and calcite deposition. Several stages left different materials in the same fossil.

The collecting story

The Gem Shop points to specific Lapidary Journal articles from 1950, 1953, 1968, 1972 and 1974. Those are verified bibliographic leads, not articles inspected in this audit. A 2019 mineralogical study adds analytical evidence to the familiar collector account.

Reading an old-stock label

No evidence here establishes that the entire locality is exhausted or that all material in trade is old stock. Keep the original locality and collecting record; “Eden Valley” and “Blue Forest” should remain distinct when documentation permits.

What we know—and what we don’t

WELL SUPPORTED: complex Eocene mineralization, broad locality and studied mineral components. UNKNOWN: current access and market range. Tree identity and provenance require specimen-specific evidence.

C&C Reference Collection

No C&C reference specimen has been authenticated for this record yet. Acquired in Oregon is not the same as formed in Oregon. Preserve an estate’s original wording and mark any lost locality documentation.

Sources & Further Reading
  1. Mustoe, Viney & Mills · Blue Forest mineralogy (2019)

    Peer-reviewed primary study. Full text and CC BY 4.0 statement inspected through author-posted ResearchGate copy.

  2. The Gem Shop · Eden Valley fossil-wood locality notes

    Specialist account and five specific Lapidary Journal issue/page leads. Treat collecting directions as historical.

  3. FossilEra · Blue Forest slab #3929

    Explicitly sold, but sale price absent. Related-item asking prices are not its transaction price.

  4. BLM · Can I Keep This?

    General personal-use petrified-wood limits; does not authorize a particular parcel or commercial collecting.

  5. CDC/NIOSH · Safe Work Practices for Silica

    Dust control guidance; wet methods are one control, not a guarantee of safe exposure.

Silica-bearing stone can release hazardous dust when cut or ground. Use appropriate dust controls; wet working alone is not a safety guarantee.