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

Lava Rock (Scoria)

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

  • Lava-rock-scoria classification

    CommonName
    Lava Rock (Scoria)
    Species
    NA
    Variety
    Colors
    Black, Dark Gray, Deep Reddish Brown
    AlternateNames
    Scoria
    GemstoneGroups
    KeySeparations
    Appearance and SG
    ClassificationComments
    Scoria 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

    ChemicalName
    ChemicalFormula
    Synthesis
    CrystalSystem
    NA
    ChemistryClassification
    Rock
    Nature
    Natural
    Crystallinity
    Aggregate
    ChemistryComments
  • Lava-rock-scoria optical properties

    Transparency
    Opaque
    Dispersion
    Strength: none
    OpticalComments
    RefractiveIndex
    Birefringence
    OpticCharacter
    NA
    OpticSign
    PolariscopeReaction
    Fluorescence
    SWUV:
    LWUV:
    CCFReaction
    Pleochroism
    None
  • Lava-rock-scoria characteristic physical properties

    Hardness
    CharacteristicComments
    Streak
    SpecificGravity
    Toughness
    Inclusions
    Lava rock or scoria will have rounded or elongated cavities.
    Luster
    Vitreous
    Stability
    Fracture
    Cleavage
    None