Beryl is extremely popular mineral, which occurs in a diversity of shapes and colors. Popular gemstone varietes include emerald, aquamarine and heliodor. Beryl is the only common source of beryllium, which is used in many hi-tech applications.
Aragonite is the less known cousin of calcite. Despite the lack of popularity, aragonite crystals and stalactites are among the most aesthetically-pleasing mineral specimes. Aragonite is present in various hydrothermal environments and it is the principal component of mollusk shells, coral skeletons and pearls.
Hematite is the abundant form of iron oxide, natural red pigment, and an integral part of the largest iron ore deposits on Earth. Highly aesthetic crystals and shiny botryoidal hematite aggregates are also very popular collector specimens.
Vivianite is found in many geological environments. Its great blue-green crystals are very rare and very popular among collectors. Also vivianite filled fossil shells are among very interesting and popular collectors items.
Molybdenite is the principal ore mineral of molybdenum and rhenium. It occurs widely in igneous and metamorphic rocks generated under high temperature conditions. Despite its lack of popularity and rare crystal forms, it is a very interesting and important industrial mineral.
Crocoite is a rare lead and chromium secondary mineral. Its rarity, bright red color, and exceptional crystal forms have guaranteed its place as a prized collection mineral. Crocoite is the first historic source of chromium and natural yellow pigment - unfortunately highly toxic.
Opal is most valued for the rich variety of colors it exhibits, their interplay in ordinary light, and their unusual range of fluorescence. These attributes have guaranteed its continuing value as a gemstone since pre-Roman times.
Rutile is a mineral of many forms and colors. It is quite widespread accessory mineral in many rocks but nice crystals are much less common. Rutile is also important source of titanium and has various industrial applications.
Vanadinite is a popular secondary mineral species of vanadium and lead, occurring as an orange-red hexagonal crystals. Like many other exotic minerals, vanadinite has a complicated history of recognition and identification.
Mineral cleaning and preparation is such a complex subject that it could easily fill a whole book. This article is a brief introduction of available mineral cleaning methods and their pros and cons.
