Red Jasper or Chert

Hardness: 6.5-7 on Mohs scale; Color: Deep red, reddish-brown; Luster: Dull to vitreous; Crystal structure: Microcrystalline quartz, no visible crystals; Cleavage: None, exhibits conchoidal fracture; Specific Gravity: 2.58-2.91

Red Jasper and Chert are varieties of cryptocrystalline quartz, formed when silica-rich sediments accumulate and undergo diagenesis. The red color is due to the presence of iron oxides (hematite). They often form in marine environments, either through the accumulation of silica skeletons of microorganisms (like diatoms or radiolarians) or by the replacement of other minerals. Geological age can vary widely, from Precambrian to Cenozoic, depending on the specific deposit.

Jasper and chert have been used for tools and weapons since prehistoric times due to their hardness and conchoidal fracture which allows for sharp edges. Today, red jasper is often used as a gemstone in cabochons, beads, and ornamental objects. It's also collected for its aesthetic appeal. Chert, when abundant, can be used as aggregate in construction.

Jasper is known as the 'supreme nurturer' and is often associated with providing grounding energy. It has been used in many ancient cultures as a carving material and for seals. The famous 'Picture Jasper' varieties display intricate patterns resembling landscapes. Chert is often found as nodules in limestone and chalk formations.

Identify it in the field by its distinct red color (though chert can be various colors including gray, black, green, and white), its hardness (it will scratch glass), and its lack of visible crystalline structure. It typically has a somewhat waxy or dull luster on unpolished surfaces and breaks with a conchoidal (shell-like) fracture. Weathered surfaces might appear rougher. It is commonly found in sedimentary rock formations, riverbeds, and beach environments around the world. For collectors, look for pieces with vibrant color or interesting banding/patterns.