[CaF] z stalactite. Here is how this specimen formed: Fluorite partially filled a small cavity f rming a geode. The outer rock matrix surrounding the geode was removed through weathering processes, exposing the outer surfac of the geode. Inside, one would likely find a hollow center with fluorite crystals growing into the open space i

The best way to determine if your specimen is a geode or concretion is to break one open with a hammer or cut one open with a wet saw. The porous texture of dinosaur eggs (right image; and other types) is quite different and easily recognizable in comparison with geodes and concretions.

2021年5月11日 · Some rubies and emeralds fluoresce red when viewed under longwave UV light, while diamonds usually fluoresce blue under UV light, and also fluoresce when bombarded with X-rays. Most pure minerals...

When individual grains are red and about the size and roundness of fish eggs, the mineral is called oolitic hematite; when it occurs in plates or scales as mica does and is steel gray, it is called micaceous or specular hematite; and when it occurs as a fine powder that can be mixed with oil and used as a paint pigment, it is called red ocher.

This is a common form for many minerals, particularly hematite and malachite, which are known for frequently forming botryoidal masses. It is also a common form of goethite, smithsonite, fluorite, and chrysocolla. Similar habits are reniform (kidney-shaped) and mammillary (breast-shaped or partial spheres).

2023年9月9日 · Fluorite, also known as fluorspar, is a widely occurring mineral found in various geological settings around the world. It is a colorful and highly valued mineral due to its vibrant fluorescence when exposed to ultraviolet light, which gives it its name.

3 天之前 · This Rocks & Geodes item is sold by CrystalMineralsWorld. Ships from Poland. Listed on Jan 30, 2025

2023年1月5日 · Most often, geodes found in Kentucky are lined with quartz crystals. Less commonly, the calcite or dolomite crystals are found on the inside, either alone or associated with bitumen, barite, galena, fluorite, quartz, limonite, sphalerite, pyrite, selenite, or celestite.

2025年1月10日 · This is a large, gemmy and fine example of the legendary "Red Glow" Ojuela fluorites from a small pocket that came out in maybe 2007-2008, and was sold even in Mexico for a super premium. However, this specimen never went to market.

One of the things that can turn people on to minerals and mineral collecting is seeing how some minerals take on unexpected colors when exposed to ultraviolet light. Shown below are paired photos of some of Wisconsin’s fluorescing minerals—plain light on the left side of the photo, shortwave ultraviolet (UV) light on the right.