Geodes are round stones that are hollow inside. Often they are filled with beautiful crystals. The shell is typically some form of chalcedony but the crystals can be of a wide range of minerals: macrocrystalline quartz, the most common crystals found in geodes, calcite, celestite, barite, limonite, dolomite, smithsonite, and others.
Geodes are a sedimentary stone that forms in both sedimentary and volcanic rock. They were once an air bubble that filled one of two ways:
by the filling of vescicles (gas bubbles) in volcanic to sub-volcanic rocks by minerals deposited from hydrothermal fluids or
by the dissolution of sedimentary nodules or concretions (that were deposited syngenetically within the rock formations in which they are found) and partial filling by the same or other minerals precipitated from diagenetic water, groundwater, or hydrothermal fluids.
Geodes are found the world over. The Warsaw formation in the central US provides us with Keokuk geodes. The Las Choyas beds in Chihuahua, Mexico, is a massive location. Outside of Tabasco, Mexico are tiny geodes, some as small as 3/8" and are also in a wide range of colors and very popular for jewelry items. Ocos are a form of geode from Brazil, very beautiful with a very thin chalcedony shell. They are typically sold in matching pairs as a collector item. We carry calcite geodes from Morocco and celestite from Madagascar. The geodes for our jewelry on this page are from the Salto do Jacui region in Rio Grande do Sul, in southern Brazil.
Geode Earrings A
Black Tabasco Geode earrings Geode 1/2 x 5/8" From top of ear wire: 1 1/4" 925 solid sterling silver
Black Agate Geode Bracelet view 1
Black Agate Geode Bracelet view 2
Black Agate Geode Bracelet view 3
Black Agate Geode Bracelet view 4
Back of bracelet; Lots of Silver!
Beautiful Black Agate Geode bracelet set in 925 Sterling Silver This beautiful item is hand made. 4 geode slices 1 oval and 3 teardrop tourmilated quartz 8 faceted clear crystal quartz
Measures 6 1/4" long, 2 1/8" wide with extensions on the chain Thickness ranges from 1/4" to 3/8" Weight 2.4 ounces or 70.94 grams There is a lot of silver in this piece
Geode pendant A
Black Agate Geode Pendant A
92.5% Sterling Silver Geode 1" x 1" Black Tourmalated Quartz 5/8" x 3/8" Faceted black onyx 3/16" Total 1 7/8" long x 1" wide Bail Opening 1/4"
Geode Pendant B
Black Agate Geode Pendant B
92.5% Sterling Silver Two Geodes
3 Faceted black onyx Total Length 2 3/8" long x 1" wide Bail Opening 1/4"
Geode Pendant C
Black Agate Geode Pendant C
92.5% Sterling Silver 7/8" x 1 1/4" Geode
3/8" Faceted black onyx Total Length 2 1/8" long x 7/8" wide Bail Opening 1/4"
Geode Pendant D
Black Agate Geode Pendant B
92.5% Sterling Silver Geode 7/8" x 3/4" Tourmilated Quartz 1/2" x 3/8"
Faceted black onyx 1/8" Total Length 1 7/8" long x 3/4" wide Bail Opening 1/4"
Geode Pendant G
Black Agate Geode Pendant G
92.5% Sterling Silver 1 1/8" x 3/4" Geode
1/2" x 5/16" Faceted black onyx Total Length 2 1/8" long x 3/4" wide Bail Opening 3/8"