10 most difficult minerals riddles A list of ten (out of 24) minerals related questions that are the most often answered incorrectly Minerals quiz The world’s largest silver producer is...?Mexico, the world's biggest silver producing country, and Poland host three each of the world's 10 biggest silver mines. China, Peru, Bolivia andTurkey host the remaining four. very hard 29% ChinaChina19%RussiaRussia14%MexicoMexico29%ChileChile37%Created by: Tschuka . Statistics based on 178 answers in 2 languages »mines riddles » Sapphire is a blue variety:Of corundum. Sapphire is a gemstone, a variety of the mineral corundum, an aluminium. It is typically blue in color, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors. Pink colored corundum may be either classified as ruby or sapphire depending on locale.very hard 32% of agateof agate30%of chalcedonyof chalcedony20%of corundumof corundum32%of jasperof jasper15%Created by: Tschuka . Statistics based on 817 answers in 3 languages »geology riddles » What's the origin of the word "turquoise"?Turkey as a country. The name Turquoise was established in the seventeenth century and came from the name of Turkey (turquois is French for "Turkish"), because the mineral was first brought to Europe from Turkey. Acient Romans called this rock Kalalit.very hard 34% Turku City in FinlandTurku City in Finland16%Turkey as a countryTurkey as a country34%Turkusy, fake regionTurkusy, fake region23%Persian tortoisePersian tortoise24%Created by: GabrielBaran. Statistics based on 4120 answers in 2 languages »gemstones riddles » According to the Mohs hardness scale, which of the given raw materials is the hardest?Orthoclase. In the order of hardness: calcite (CaCO3), fluorite (CaF2), apatite (Ca5 (PO4) 3 (OH-, Cl-, F-), and orthoclase (KAlSi3O8).very hard 35% calcitecalcite37%orthoclaseorthoclase35%fluoritefluorite9%apatiteapatite18%Created by: Tschuka . Statistics based on 450 answers in 2 languages » Which of these elements is not a "rare earth metal"?Rhodium. Despite their name, rare-earth elements are – with the exception of the radioactive promethium – relatively plentiful in Earth's crust, with cerium being the 25th most abundant element at 68 parts per million, or as abundant as copper. They find application in the most dynamically developing areas of high technology industry such as: aviation, space flights, production of mobile phones (smartphones).very hard 39% RhodiumRhodium39%SamariumSamarium21%ScandiumScandium23%EuropiumEuropium15%Created by: Tschuka . Statistics based on 734 answers in 3 languages »chemistry riddles » The only color which sapphire cannot be is ...Red. The only color which sapphire cannot be is red – as red colored corundum is called ruby, another corundum variety. Pink colored corundum may be either classified as ruby or sapphire depending on locale.very hard 39% orangeorange21%yellowyellow14%redred39%blackblack24%Created by: Tschuka . Statistics based on 238 answers in 2 languages » Which of the following is not an allotropic variety of coal?Anthracite. An allotropy is a phenomenon of appearing, in the same state of aggregation, of all sorts varieties of the same chemical element, differing in physical properties and chemical. Coal is appearing mainly in the form of diamond, graphite, fullerene and graphene. Anthracite is simply a variety of the hard bituminous coal.hard 40% diamonddiamond11%graphitegraphite11%fullerenefullerene37%anthraciteanthracite40%Created by: Paweł Kołodziejczyk. Statistics based on 6496 answers in 2 languages »chemistry riddles » What is karst?A kind of chemical decomposition. Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions.hard 45% a kind of physical decompositiona kind of physical decomposition25%a kind of chemical decompositiona kind of chemical decomposition45%a kind of biological decompositiona kind of biological decomposition13%none of the abovenone of the above15%Created by: Ninjai. Statistics based on 16036 answers in 2 languages »rocks riddles » Which of the minerals below shows pleochroism?Alexandrite. Pleochroism is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light. Alexandrite appears greenish in daylight where the full spectrum of visible light is present, and reddish in incandescent light which emits less green and blue spectrum.hard 46% aquamarineaquamarine22%bixbitebixbite11%alexandritealexandrite46%topaztopaz19%Created by: Ninjai. Statistics based on 226 answers in 2 languages »geology riddles » What mineral is a heliodor gemstone a variety of?Beryl. Heliodor is a yellow transparent variety of beryllium (emerald and aquamarine are also varieties of beryllium). The name derives from the Greek word helios = sun (sun-god) and doron = gift ("gift of the Sun").hard 47% TopazTopaz27%RubyRuby12%BerylBeryl47%TalcTalc11%Created by: Paweł Kołodziejczyk. Statistics based on 10779 answers in 3 languages »names riddles » Play minerals quiz and see all the questions.