Wyoming blue petrified wood tree  branch offers botryoidal skin and with detailed patterns.

Petrified Wood 'Pepper Tree' Schinoxylon Green River Fm. WY" is distinct from "Blue Forest" petrified wood, although they share the same broader geological origin.

Here's a breakdown to clarify:

1. Green River Formation, Wyoming: This is a vast, Eocene-age (around 50 million years old) geological formation in the western US, famous for its beautifully preserved fossils, including fish, insects, plants, and petrified wood. "Green River Fm." simply indicates the geological layer where the fossil originated.

2. "Blue Forest" Locality: This is a specific, famous collecting area within the broader Green River Formation, located in the Eden Valley of Sweetwater County, Wyoming. The name "Blue Forest" refers to the unique and highly prized blue coloration of the chalcedony that often infills the wood from this particular site.

   • Distinctive Blue Forest Characteristics:
     • Algae/Stromatolite Casts: Trees often fell into shallow, algae-rich parts of an ancient lake (Lake Gosiute). The wood became encased by thick calcareous stromatolitic (algal) coatings, which preserved the outer bark and prevented decay.
     • Blue Chalcedony/Agate: After the wood silicified, the spaces within the algal casts and between the original wood fibers were often filled with light blue chalcedony or agate. This blue hue is typically due to trace amounts of copper, manganese, titanium, and/or iron.
     • Tree Species: While various tree species are found, common ones associated with Blue Forest include sycamore, laurel, holly, and sometimes palm. Significantly, Schinoxylon is also found at the Blue Forest locality.

3. "Pepper Tree" Schinoxylon:

   • Schinoxylon is a specific genus of ancient tree (a type of dicot wood, or hardwood, from the pepper tree family) that was common in the Eocene forests around Lake Gosiute.
   • Commonality: Schinoxylon is widely found as petrified wood throughout the Green River Formation, and indeed, it is one of the most common types of wood found at the Blue Forest locality itself.

The Distinction:

The key difference lies in the specific conditions of fossilization and the resulting mineral infill, not solely the original tree species.

• A piece of petrified Schinoxylon from the Green River Formation might not have been subject to the unique algal casing and specific mineral-rich groundwater that led to the distinctive blue chalcedony and detailed preservation characteristic of the "Blue Forest" locality. It might have different colors (like your red, black, and yellow piece), different types of infill, or less intricate preservation.
• Conversely, "Blue Forest" petrified wood can be Schinoxylon (and often is!), but it's specifically those pieces that exhibit the signature blue chalcedony, algal casts, and highly detailed preservation that makes them "Blue Forest