High quality MOSASAURUS Tooth with sharp edges, perfect tip. The bottom provides a good view of the enamel and dentin. This tooth is from late Cretaceous age, about 70 million years ago. Length is 1.8 inches. Slight wear on one edge.

This brilliant cluster of BRAZILIANITE crystals is translucent. The longest crystal is 1.0 inch. Color is green with a hint of yellow. The luster is vitreous. This specimen is from the collection of Roger Maynard. Roger is a friend and was a long-time geologist with the US Geological Survey.

Slice from a cluster of RHODOCHROSITE STALACTITES from the famous Capillitas mine in Argentina. The dozens of creme-colored “straws” are quite striking. Three years ago, the mine was taken over by the government to mine silver and copper. No more Rhodochrosite will come from this mine.

Cross section of a RHODOCHROSITE STALACTITE from the famous Capillitas mine in Argentina. Since most of the Rhodochrosite from this mine is sold to make jewelry, it is priced according to weight. This piece weighs 25 grams. At US$8 per gram, the price is $200. Three years ago, the mine was taken over by the government to mine silver and copper. No more Rhodochrosite will come from this mine.

Cross section of a RHODOCHROSITE STALACTITE from the famous Capillitas mine in Argentina. Since most of the Rhodochrosite from this mine is sold to make jewelry, it is priced according to weight. This piece weighs 42 grams. At US$8 per gram, the price is $336. Three years ago, the mine was taken over by the government to mine silver and copper. No more Rhodochrosite will come from this mine.

Cluster of bipyramidal CALCITE crystals with a maroon color, most likely from inclusions of iron. The largest crystal is 1.5 inches in length. The specimen is museum size, 6.1 inches in length. This specimen is from the collection of Roger Maynard. Roger is a friend and was a long-time geologist with the US Geological Survey.

This piece glitters! Stunning color contrast of green Siderite “Blades” with brassy iridescent Chalcopyrite, whitish Calcite, and gray Tetrahedrite crystals in this specimen. The green blades of Siderite in this piece are very rare! Several of the Siderite blades are at least 0.5 inch long. The Calcite crystals are flattened and translucent. The luster of the Siderite is vitreous while the Chalcopyrite and Tetrahedrite have a brilliant metallic luster.

Cluster of large, green, translucent FLUORITE crystals with several CALCITE crystals. The Fluorite fluoresces Blue under long-wave UV light. Specimen is 6.1 inches in length. Largest Fluorite cube is 3.5 inches long. All Fluorite crystals have beveled edges, usually with etching. This specimen is from the collection of Roger Maynard. Roger is a friend and was a long-time geologist with the US Geological Survey.

Cluster of brilliant emerald-green Dioptase crystals on matrix. The largest dioptase crystal is 0.4 inches. Crystals are rhombohedral shape. The specimen is from the type location for dioptase: Altyn-Tyube deposit, Karaganda Region, Kazakhstan.

Stibnite is an Antimony Sulfide mineral. This specimen has one primary Stibnite crystal 5.4 inches long that is terminated at one end. The color is silver-gray. It has a metallic luster. The piece has many minor Stibnite crystals at one end. 

This specimen is entirely translucent Hyalite Opal except for a little bit of dirt on the bottom that I could not clean off. The Hyalite fluoresces a brilliant green under a short-wave UV light. 

The Hyalite Opal is the clear, globular layer on top of the white Milk Opal in this specimen. The Hyalite fluoresces a brilliant green under a short-wave UV light. 

Reddish-Pink RHODOCHROSITE with minor Tetrahedrite and Chalcopyrite from The Sweet Home Mine in Colorado.

Reddish-Pink RHODOCHROSITE with minor Tetrahedrite and Pyrite from The Sweet Home Mine in Colorado.

Reddish-Pink RHODOCHROSITE with minor Galena and Pyrite from The Sweet Home Mine in Colorado.

Vitreous black TOURMALINE from the Harney Peak Pegmatite of South Dakota.

Beautiful honey-brown Barite rosettes and shimmering Marcasite on Schalenblende stalactites.

Cluster of brilliant emerald-green Dioptase crystals on matrix. The largest dioptase crystal is 0.5 inches. Crystals are rhombohedral shape. The specimen is from the type location for dioptase: Altyn-Tyube deposit, Karaganda Region, Kazakhstan.

Stibnite is an Antimony Sulfide mineral. This complex cluster has Stibnite blades as long as 4 inches. The color is silver. It has a brilliant metallic luster. The piece has minor white Calcite blades. 

Unique specimen of white Colemanite crystals. A calcium borate mineral from Death Valley, California. The specimen was legally recovered prior to 2011.