Wheat sheaf bundles of parallel growth calcite crystals on a yellow/brown fluorite matrix, from Cave-In-Rock, Hardin County, Illinois. Under short wave UV, the calcite shows a bright blue/white fluorescent response with brief dim phosphorescence. Under long wave UV, the response is a warmer white. The fluorite matrix is poorly fluorescent. This specimen measures 64.1 x 57 x 44.5 mm, and weighs 86 grams.
![](https://static.wixstatic.com/media/c24caa_a13874c12cc442378d26752dca4ce300~mv2.png/v1/fill/w_980,h_662,al_c,q_90,usm_0.66_1.00_0.01,enc_auto/c24caa_a13874c12cc442378d26752dca4ce300~mv2.png)
Under short wave UV (254 nm), the calcite shows a ghostly blue-white fluorescent response.
![](https://static.wixstatic.com/media/c24caa_1185941579e24ea08b8da9e1e73c241d~mv2.png/v1/fill/w_980,h_666,al_c,q_90,usm_0.66_1.00_0.01,enc_auto/c24caa_1185941579e24ea08b8da9e1e73c241d~mv2.png)
Creamy, off-white fluorescence is seen under long wave UV (365 nm).
![](https://static.wixstatic.com/media/c24caa_ac62362473b84792bdc0155872fb8897~mv2.png/v1/fill/w_980,h_665,al_c,q_90,usm_0.66_1.00_0.01,enc_auto/c24caa_ac62362473b84792bdc0155872fb8897~mv2.png)
Same specimen shown under visible light.