Xaxim

Organic

By Tim Matthews, JD, FGA, GG, DGA,
CEO and President of JTV (retired)
Published: June 2014
Modified: September 2023
Xaxim Polished

Xaxim is a type of petrified tree fern from a period of time even before the dinosaurs roamed the earth. Estimated to be some 270 million years old, these fossilized specimens offer an exciting window into the past. Similar in appearance to the palm tree, xaxim trees can still be found growing in Brazil today. However, they grow very slowly, averaging about 3 inches every 10 years. Featuring all natural color with no enhancement, xaxim is prized by fossil collectors across the globe.

General Information

Common Name
Xaxim
Species
Organic
Transparency
Semitransparent - Semitranslucent
Dispersion
Strength: None
Refractive Index
1.539-1.535
Birefringence
0.004
Optic Character
Uniaxial
Optic Sign
Positive
Polariscope Reaction
Aggregate (AGG)
Fluorescence
SWUV: Inert
LWUV: Inert
Pleochroism
None
Hardness
6.5-7
Specific Gravity
2.550-2.700 Typical:2.600
Toughness
Excellent
Inclusions
Xaxim's cellular appearance comes from the cross section structure of the fern.
Luster
Vitreous, Greasy
Stability
Good
Fracture
Conchoidal, Granular
Cleavage
None
Chemical Name
silicon dioxide (aka silica)
Chemical Formula
SiO2
Crystal System
Trigonal
Chemistry Classification
Silicate

Xaxim Colors

  • Brown Xaxim
    Brown
  • Pink Xaxim
    Pink
  • Yellow Xaxim
    Yellow

Alternate Names

Fossilized Tree Fern, Agatized Fossil Tree Fern, Petrified Tree Fern

Countries of Origin

Unknown; Brazil

Care

Normal care