from Greek porphyros (purple); a reddish-purple rock highly resistant to erosion. Many sarcophagi were made from porphyry
Any igneous rock in which relatively large, conspicuous crystals (phenocrysts) are set in fine-grained groundmass.
A term used somewhat loosely to designate a rock consisting of a fine-grained base (usually feldspathic) through which crystals, as of feldspar or quartz, are disseminated. There are red, purple, and green varieties, which are highly esteemed as marbles.
Any igneous rock in which large conspicuous crystals are enclosed by a fine grained groundmass.
A term used to describe the texture of an igneous rock in which relatively large mineral crystals, called phenocrysts, are set in a fine grained matrix.
An igneous rock containing abundant phenocrysts suspended in a finely crystalline matrix.
a very hard stone with a reddish-purple colour; found only in Egypt and often associated with imperial sculpture.
(por'-phyry) An igneous rock that contains larger crystals in a fine-grained groundmass or matrix typically indicating at least two rates of cooling and crystallization.
Light-colored, fine-grained intrusive igneous rock with some conspicuously large crystals of quartz, feldspar, or biotite.
a reddish-purple rock consisting of large crystals of feldspar in a finer groundmass of feldspar, hornblende, etc.
porphyritic an igneous rock with large crystals enclosed in a fine matrix
Any igneous rocks with a porphyritic texture, that is, coarse crystals in a fine groundmass. Indicates that two phases of cooling were involved.
An igneous rock in which relatively large and conspicuous crystals (phenocrysts) are set in a matrix of finer crystals.
An igneous rock of any composition containing conspicuous phenocrysts (large well-formed crystals) in a fine-grained groundmass.
any igneous rock with crystals embedded in a finer groundmass of minerals
An igneous rock, usually a dike or sill, with larger, generally conspicuous, early-formed crystals contained within a matrix of much smaller crystals.
An igneous rocks which has porphyritic texture.
an igneous rock of any composition that contains conspicuous pheno-crysts (larger, well-formed mineral grains) in a finer-grained groundmass. The pre-sence of phenocrysts implies two stages (speeds) of cooling of the original magma.
igneous rocks containing large crystals in a fine-grained groundmass
rock of feldspar crystals embedded in a compact dark red or purple groundmass
Any igneous rock in which relatively large crystals, called phenocrysts, are set in a fine-grained ground mass.
An igneous rock of any composition that contains conspicuous phenocrysts in a fine-grained groundmass; a porphyritic igneous rock
Generally a body of intrusive rock containing relatively large crystals in a fine-grained groundmass. Often associated with large tonnage copper deposits which may be amenable to open pit mining.
An igneous rock characterized by visible crystals in a fine-grained matrix.
An igneous rock in which relatively large crystals (phenocrysts) constitute 25% or more of the volume and are set in a fine-grained ground mass. Can also be used in conjunction with a mineral name where the phenocrysts are of the named mineral e.g. quartz porphyry;
an igneous rock in which coarse euhedral crystals are scattered through a groundmass of finer-grained minerals or a glassy matrix. [AHDOS
Porphyry is a variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz, dispersed in a fine-grained feldspathic matrix or groundmass. The larger crystals are called phenocrysts. In its non-geologic, traditional use, the term "porphyry" refers to the purple-red form of this stone, valued for its appearance.