Tasmanite
{{Short description|Sedimentary rock}}
{{Other uses|List of minerals named Tasmanite}}
{{distinguish|Tanzanite}}
Tasmanite is a sedimentary rock type almost entirely consisting of the prasinophyte alga Tasmanites. It is commonly associated with high-latitude, nutrient-rich, marginal marine settings found in Tasmania.Peters, K.E., C.C. Walters & P.J. Mankiewicz, 2006, Evaluation of kinetic uncertainty in numerical models of petroleum generation, American Association of Petroleum Geologists Bulletin, 90, 387–403. It is classified as marine type oil shale.Hutton, A.C. 1987. Petrographic classification of oil shales // Intern. J. Coal Geol. 1987. Vol. 8. P. 203–231. It is found in many oil-prone source rocks and, when present, contributes to the oil generation potential of the rock. Some sources also produce a red-brown translucent material similar to amber which has also been called tasmanite.
In 1865, Professor A. J. Church, near the floodplain of the Mersey River (Northern Tasmania), found translucent reddish-brown or brown samples of an unknown mineral resembling amber embedded in shale in one of the small Tasmanite deposits. These differences ultimately amounted to up to 40% of the main rock and had the appearance of narrow, scaly lenses, difficult to separate from the main rock. Professor Church carried out laboratory chemical analysis and made a detailed description of the new mineral, naming it by the same name as the parent rock: Tasmanite.Сhurch N. J., The latest research into the landscape of Northern Tasmania and its natural minerals. — 1865, р. 480. Later, the trivial name “Tasmanian amber” was assigned to it.