The fluorescent minerals in the specimen are chalcedony and calcite (in some specimens) from the Badlands of South Dakota.

The first image was taken under a short wave ultraviolet light. The chalcedony fluoresces various shades of green. Any calcite present will fluoresce pink to pinkish-red. There does seem to be a small amount of calcite present in the upper left and lower right in the photo of the specimen. Any purple areas are the reflection of the short wave light off the normally light tan to grey non-fluorescing minerals of the specimen.

The second image below was taken under long wave ultraviolet light. The shades of purple color are due to the long wave light reflecting off the light colored minerals in the specimen which do not fluorescence under long wave.

For other images of this mineral, go back to the main fluorescent page and click on the view specimen material from South Dakota link.

Sponge-fossil
	Quantity in Basket: None Code: SDS-102 Price: $40.00 Shipping Weight: 0.65 pounds
	Quantity:
Time: Oligocene, 37.5-26 million years ago. Location: Badlands of South Dakota Minerals: Chalcedony and Calcite Size: 4-1/2" x 3-1/4" x 1-1/4"