Lava Rock (Scoria) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Also known as scoria, lava rock is formed from solidified volcanic lava. A defining feature of this rock is cavities caused by trapped gas bubbles. Unlike pumice, however, lava rock does not float on water. The unique look of this highly porous rock, along with its relatively light weight, makes it popular for jewelry and ornamental carvings.
Colors
Black, Dark Gray, Deep Reddish Brown
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Lava-rock-scoria classification
CommonNameLava Rock (Scoria)SpeciesNAVarietyColorsBlack, Dark Gray, Deep Reddish BrownAlternateNamesScoriaGemstoneGroupsKeySeparationsAppearance and SGClassificationCommentsScoria is an igneous rock that is formed from solidified lava. The cavities are caused by trapped gas bubbles. Scoria can be separated from pumice because it will sink in water because it has an SG greater than 1. -
Lava-rock-scoria chemistry & crystallography
ChemicalNameChemicalFormulaSynthesisCrystalSystemNAChemistryClassificationRockNatureNaturalCrystallinityAggregateChemistryComments -
Lava-rock-scoria optical properties
TransparencyOpaqueDispersionStrength: noneOpticalCommentsRefractiveIndexBirefringenceOpticCharacterNAOpticSignPolariscopeReactionFluorescenceSWUV:
LWUV:CCFReactionPleochroismNone -
Lava-rock-scoria characteristic physical properties
HardnessCharacteristicCommentsStreakSpecificGravityToughnessInclusionsLava rock or scoria will have rounded or elongated cavities.LusterVitreousStabilityFractureCleavageNone