Search results
Results from the WOW.Com Content Network
It often occurs as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore". It crystallizes in the tetragonal system, often occurring as stubby, pyramidal or tabular crystals. It also occurs as earthy, granular ...
A geode (/ ˈ dʒ iː. oʊ d /; from Ancient Greek γεώδης (geṓdēs) ' earthlike ') is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded.
The world's largest known geode, a celestine geode 35 feet (11 m) in diameter at its widest point, is located near the village of Put-in-Bay, Ohio, on South Bass Island in Lake Erie. The geode has been converted into a viewing cave, Crystal Cave, with the crystals which once composed the floor of the geode removed. The geode has celestine ...
The colors of Scottish agates vary, and bands may be different shades of blue, grey, purple, pink, brown, orange, or red. Pot stones or potato stones are irregular agate nodules or geodes found in Bristol and Somerset, England. They typically consist of a reddish, banded agate surrounding a hollow cavity lined with macroscopic quartz, although ...
Like amethyst, heat-treated amethyst often exhibits color zoning, or uneven color distribution throughout the crystal. In geodes and clusters, the color is usually deepest near the tips. [9] Unlike heat-treated amethyst, natural citrine typically exhibits even coloration throughout the crystal and never occurs in geodes or clusters.
Chabazite crystallizes in the triclinic crystal system with typically rhombohedral shaped crystals [4] that are pseudo-cubic. The crystals are typically twinned, and both contact twinning and penetration twinning may be observed. They may be colorless, white, orange, brown, pink, green, or yellow.
Enhydro geode, found in Brazil. Enhydro agates are nodules, agates, or geodes with water trapped inside its cavity. [1] Enhydros are closely related to fluid inclusions, but are composed of chalcedony. The formation of enhydros is still an ongoing process, with specimens dated back to the Eocene Epoch. [2]
In some compositions, at high pressures without water crystallization of enstatite is favored, but in the presence of water at high pressures, olivine is favored. [ 12 ] Granitic magmas provide additional examples of how melts of generally similar composition and temperature, but at different pressure, may crystallize different minerals.