The Gem and Mineral Show has come and passed again in Tucson. The city was full of rock hounds and gem collectors, the hotels were booked and traffic was as bad as it is on game days. On the southwest corner of Sixth Avenue and Sixth Street, however, the Conrad Wilde Gallery welcomes this yearly infiltration with an exhibit that is, quite literally, down to earth.

This month’s exhibit at the Conrad Wilde, which opened Feb. 6, is called “”Geologic Time.”” It’s a tribute to the natural and geologic processes of our world. Works from four different artists express and evaluate the concepts of erosion, layers, the elements and time through a variety of media.

The selections from the “”Crater”” series, created by Marc Leone, are made of archival paper and graphite. The paper has been eroded by hand and with tools into various layers, and then shaded and contoured with graphite. This process leaves the viewer with the impression of moonscapes in gritty and grounded detail. The numerical titles of the pieces, such as “”Crater #2001,”” imply a project that has been in process and undergoing evolution for eons.

Similarly, Laura Moriarty’s work is also based in layers. However, hers are brought to life in earthy greens, blues, oranges and pinks. Reminiscent of Dr. Seuss’ landscapes, each is representative of a specific geological process or phenomenon found naturally. Titles like “”The Expansive Force of Water Freezing in Cracks”” and “”Buried Landscape Unconformity”” bring to mind reference pages in a colorful, touchable encyclopedia of Earth. Moriarty uses encaustic, a combinative process of beeswax and resin, to create these unique layers over wood panels.

The four artists showcased in “”Geologic Time”” represent a wide range of styles, techniques and intentions. However, the show works well together; the space is ample enough that each piece can be experienced individually or in sequence. And although each artist’s vision is different, the similar subject matter brings about likenesses among the works. The color palette is muted and earth-based throughout the show, as if each piece belonged with another. Each one begs to be touched; though they are hanging on the wall, the layers and shapes call for tactile exploration, making the viewer want to dig their fingers into the earth of “”Geologic Time.””

If you go

“”Geologic Time””

Conrad Wilde Gallery

439 N. Sixth Ave. #171

Runs through Feb. 27

Tuesday-Saturday

11 a.m. – 5 p.m.