Xaxim Gemstone & Information | Gemopedia by JTV | Gemopedia™

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.
Colors
Tan, Cream, Brown, Orange, White, Gray, Black, Yellow, Red
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Xaxim classification
CommonNameXaximSpeciesQuartzVarietyChalcedonyColorsTan, Cream, Brown, Orange, White, Gray, Black, Yellow, RedAlternateNamesFossilized Tree Fern, Agatized Fossil Tree Fern, Petrified Tree FernGemstoneGroupsKeySeparationsRI, SG, appearance and fractureClassificationCommentsXaxim is estimated to be 270 million years old. -
Xaxim chemistry & crystallography
ChemicalNamesilicon dioxide (aka silica)ChemicalFormulaSiO2SynthesisCrystalSystemTrigonalChemistryClassificationSilicateNatureNaturalCrystallinityAggregateChemistryComments -
Xaxim optical properties
TransparencySemitransparent - SemitranslucentDispersionStrength: noneOpticalCommentsRefractiveIndex1.539-1.535Birefringence0.004-0.004OpticCharacterUniaxialOpticSignPositivePolariscopeReactionAggregate (AGG)FluorescenceSWUV: Inert
LWUV: InertCCFReactionPleochroismNone -
Xaxim characteristic physical properties
Hardness6.5-7CharacteristicCommentsStreakSpecificGravity2.55-2.7 Typical:2.6ToughnessExcellentInclusionsXaxim's cellular appearance comes from the cross section structure of the fern.LusterVitreousStabilityGoodFractureConchoidal, GranularCleavageNone