Concentric – Circular ring aggregates around a center
This habit is found in cross-sections from reniform/mamillary habits, and also from elongated stalactites of amethyst (quartz), malachites, rhodocrosite, and others Common exampl
Columnar – Similar to bladed and radial: Long, slender prisms often with parallel growth
Common examples: calcite, gypsum/selenite
Bladed – Blade-like ends, slender and somewhat flattened
Common examples: quartz, stilbite, kyanite
Acicular – Needle-like, slender and/or tapered
Acicular, in mineralogy, refers to a crystal habit composed of slender, needle-like crystals. Crystals with this habit tend to be fragile. Complete, undamaged a
Oltu stone aka black amber, a kind of jet
Oltu stone (Turkish: Oltu taşı) is a kind of jet found in the region around Oltu town within Erzurum Province, eastern Turkey. The organic
Jet
Jet is a type of lignite, the lowest rank of coal, and is a gemstone. Unlike many gemstones, jet is not a mineral, but is rather a mineraloid. It is derived from wood tha
Wood Opal
Wood opal is a form of petrified wood which has developed an opalescent sheen or, more rarely, where the wood has been completely replaced by opal. Other names for this opalize
Petrified Wood
Petrified wood, also known as petrified tree (from Ancient Greek πέτρα meaning ‘rock’ or ‘stone’; literally ‘wood turned into stone’),
Tongue stone
According to Renaissance accounts, large, triangular fossil teeth often found embedded in rocky formations were believed to be petrified tongues of dragons and snakes and so
Toadstone aka bufonite
The toadstone, also known as bufonite (from Latin bufo, “toad”), is a mythical stone or gem that was thought to be found in the head of a toad. It was supposed
Lyngurium
Lyngurium or Ligurium is the name of a mythical gemstone believed to be formed of the solidified urine of the lynx (the best ones comin
Shaligram
A shaligram, or shaligrama shila (Devanagari: शालिग्राम शिला Śāligrāma-śilā), is a particular variety of stone collected from riverbed or banks
Madstone
In the folklore of the early United States, a madstone was a special medicinal substance that, when pressed into an animal bite, was believed to prevent rabies by drawing th
Adder stone aka hag stone
An adder stone is a type of stone, usually glassy, with a naturally occurring hole through it. Such stones, which usually consist of flint, have been discovered by archaeologis
Snake stone aka viper stone, snake pearl, black stone, serpent stone and nagamani
A snake-stone, also known as a viper’s stone, snake’s pearl, black stone, serpent-stone, or nagamani is an animal bone or stone used as folk medicine for snake b
Goa stone
A Goa stone or Lapis de Goa was a man-made bezoar that was considered to have medicinal and talismanic properties. Goa stones were made in Goa, India and exported to apo