pseudomorphs
False crystal forms
Pseudomorphs are minerals that have taken on the external crystal form of a different mineral, replacing the original while retaining its shape.
The original mineral dissolves or transforms while a new mineral fills the space, creating a kind of geological impostor: The quartz pseudomorphs after fluorite preserved the cubic crystal habit.
The term extends to any object that has taken another's form without sharing its substance.
Ordered-atom solid
- quartzCrystalline silicon dioxide
- calciteCrystalline calcium carbonate
- limoniteHydrated iron oxide ore
- malachiteGreen copper carbonate stone
azurite · pyrite · cassiterite · feldspar · gypsum · halite · silicate · replacement
Organic remains becoming mineral
- petrificationBecoming rock-like
- agateBanded semiprecious stone
- chalcedonyTranslucent microcrystalline silica variety
- sedimentParticles settling in liquid
strata · formation · ore · vein · hydrothermal · dissolution · precipitation · groundwater
What takes another's place
- substitutionExchange of one for another
- alterationAct of modifying
- conversionAct of changing states
- preservationMaintaining something's condition
transmutation · metamorphosis · dissolution · infilling · encrustation · oxidation · weathering · leaching
Faithful scaled reproduction
- facsimileExact reproduction of original
- copyIdentical reproduction made
- castPerformers, throw, or splint
- moldForm-giving container
impression · simulacrum · preservation · ghost · outline · shell · husk · remnant
crystal
Ordered-atom solid
- quartzCrystalline silicon dioxide
- calciteCrystalline calcium carbonate
- limoniteHydrated iron oxide ore
malachite · azurite · pyrite · cassiterite · feldspar · gypsum · halite · silicate · replacement · alteration
fossilization
Organic remains becoming mineral
- petrificationBecoming rock-like
- agateBanded semiprecious stone
- chalcedonyTranslucent microcrystalline silica variety
sediment · strata · formation · ore · vein · hydrothermal · dissolution · precipitation · groundwater · replacement
replacement
What takes another's place
- substitutionExchange of one for another
- alterationAct of modifying
- conversionAct of changing states
preservation · transmutation · metamorphosis · dissolution · infilling · encrustation · oxidation · weathering · leaching · recrystallization
replica
Faithful scaled reproduction
- facsimileExact reproduction of original
- copyIdentical reproduction made
- castPerformers, throw, or splint
mold · impression · simulacrum · preservation · ghost · outline · shell · husk · remnant · trace