Porphyry (geology)
Videos
Porphyry is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass. In its
"Imperial Porphyry" from the Red Sea Mountains of Egypt
A waterworn cobble of porphyry
Rhyolite porphyry from Colorado; scale bar in lower left is 1 cm (0.39 in)
Igneous porphyry from the Hunter Mountain pluton in the Last Chance Range in Death Valley National Park
The Portrait of the Four Tetrarchs is a porphyry sculpture group of four Roman emperors dating from around 300 AD. The sculptural group has been fixed to a corner of the façade of St Mark's Basilica i
Porphyry (geology)
…Kilimanjaro), Mount Erebus near the Ross Sea in Antarctica, the Oslo graben in Norway, and south-central British Columbia. Use in art and architecture The Tetrarchs, a porphyry sculpture sacked from the Byzantine Philadelphion palace in 1204, Treasury of St. Marks, Venice Carmagnola, an imperial porphyry head in…
Portraits of the Four Tetrarchs, porphyry, c. 305 A.D., embedded in the façade of St. Mark's Basilica, Venice
Portrait of the Four Tetrarchs (head and torso detail-group of four)
Missing heel portion kept in the Istanbul Archaeology Museum
Detail