5.6" Polished Banded Agate with Wegeler Effect - Kerrouchen, Morocco

This is a gorgeous polished agate nodule half that was collected from the Khenifra Province of Morocco. It features plume-like formations around the walls of the nodule which are encapsulated in agate. The white and translucent banding of this agate results in this specimen exhibiting a wegeler effect when rotated.

One side of this specimen has been cut flat and polished to a glossy finish, while the other side and outer edge have been left rough. This agate specimen comes with an acrylic display stand.

The wegeler effect, also known as the shadow effect or parallax effect, is a three-dimensional oddity in which rotating the agate results in the appearance of lines that move. One line will move with the source of light while the other moves with your point of view. This occurs in agate that has tightly packed, alternating bright opaque bands and transparent bands.

Banded agate nodules from Kerrouchen (also spelled Karouchen or Kerrouchene) are known for their intense red, pink, white, yellow, orange and brown agate hues. They formed as nodules from silica and iron-rich fluids, within the Triassic age basaltic rock. These nodules can reach upwards of 12 inches wide and can be collected from the basalt itself. More commonly, they're collected from apple farms in the valleys where farming processes expose these nodules that erode from the basalt. Both nodular and vein/seam agates come from this region.

Agate is a variety of microcrystalline quartz (chalcedony) that displays translucence and in some cases banding. Agate primarily forms when silica-rich fluids fill pockets within rock and/or fossils, resulting in deposition of the silica along the walls of the rock. This process can result in banding patterns as the composition and impurities of the fluids change over time. These banding patterns can either form as flat layers or rounded layers, depending on the surfaces available for deposition.

Chalcedony var. Agate
Kerrouchen, Khenifra Province, Morocco
5.6 x 5", up to 2.05" thick