Dendritic Quartz Gemstone & Information | Gemopedia by JTV | Gemopedia™
This agate variety is termed "dendritic" due to its internal collection of dendrites. Dendrites are fern-like inclusions of iron, manganese, or other metallic oxides that create bold patterns within the gem. Typically, dendritic agates are cut into slabs to best exhibit nature's artwork. As you might guess, these pieces are one-of-a-kinds, as no two dendritic patterns are exactly the same. The internal dendrites may appear black, dark gray, brown or green and, in rare instances, even red.
Colorless, Brown, Orange, Yellow
Dendritic-quartz classificationCommonNameDendritic QuartzSpeciesQuartzVarietyDendritic QuartzColorsColorless, Brown, Orange, YellowAlternateNamesGemstoneGroupsKeySeparationsRefractive index, appearance, birefringence, optic character and optic figure. A bull's-eye optic figure is determinative for quartz; may also show Airy's spiral optic figure and Brazil-law twinning under crossed polarizing filters.ClassificationCommentsDendrites are crystals that grow in a fractal pattern and have an appearance similar to moss or branches.
Dendritic-quartz chemistry & crystallographyChemicalNamesilicon dioxide (aka silica)ChemicalFormulaSiO2SynthesisCrystalSystemTrigonalChemistryClassificationSilicateNatureNaturalCrystallinityCrystallineChemistryComments
Dendritic-quartz optical propertiesTransparencyTransparent - TranslucentDispersionStrength: weak fire Value: 0.013OpticalCommentsRefractiveIndex1.544-1.553
Tolerance:very constantBirefringence0.009OpticCharacterUniaxialOpticSignPositivePolariscopeReactionDoubly Refractive (DR)FluorescenceSWUV:
Dendritic-quartz characteristic physical propertiesHardness7CharacteristicCommentsStreakWhiteSpecificGravity2.64-2.69 Typical:2.66ToughnessGoodInclusionsDendritic quartz will have dendrite inclusions and may contain liquid, two-phase and three-phase inclusions, negative crystals, minerals, needles, rutile and iron particles.LusterVitreousStabilityGoodFractureConchoidalCleavageNone