6.2" Polished Olivine Peridot Slab - Washington

About Peridot

Peridot is a magnesium iron silicate mineral with the basic chemical formula Mg2SiO4. It is a gem variety of the mineral forsterite, and ranges between yellow, olive, and brownish green depending on the amount of iron present during formation. Dark, olive green-colored peridot gems are typically the most sought after. Peridot was originally named as topaz and was used for a variety of reasons, whether it be during the Crusades as a way to adorn religious objects, or even thought by many to posses medicinal powers. For unknown reasons, the original name was removed and given to the mineral that most know as topaz today, sometime during the 18th century.

Many gem-quality specimens were originally in basalt nodules in the Earth's mantle, and were fragmented and brought to the surface by volcanic activity. Large peridot crystals are often found in some types of rare, stony-iron meteorites know as pallasites.

About Magnetite

Magnetite is a naturally occurring iron oxide mineral with the chemical formula Fe₃O₄. It is one of the most magnetic minerals found on Earth, a property that has made it historically significant in the development of early navigation tools like the compass. Magnetite typically forms in igneous and metamorphic rocks, and its crystals often appear as octahedrons or granular masses with a metallic luster and a deep black to dark gray color.

The mineral is composed of both ferrous (Fe²⁺) and ferric (Fe³⁺) iron, giving it its strong magnetic characteristics and distinguishing it from other iron oxides such as hematite. It has a Mohs hardness of 5.5–6.5 and a high specific gravity, making it quite dense. Magnetite is an important iron ore and is widely mined for use in steel production.

Besides its industrial value, magnetite is also of interest to collectors due to its striking appearance and magnetic properties. Large or well-formed octahedral crystals are particularly sought after.