rankinite
A monoclinic-prismatic mineral containing calcium, oxygen, and silicon.

ransomite
A monoclinic-prismatic blue mineral containing copper, hydrogen, iron, oxygen, and sulfur.

ranunculite
A monoclinic mineral containing aluminum, hydrogen, oxygen, phosphorus, and uranium.

rapidcreekite
An orthorhombic-dipyramidal mineral containing calcium, carbon, hydrogen, oxygen, and sulfur.

rappoldite
A triclinic-pinacoidal mineral containing arsenic, cobalt, hydrogen, lead, nickel, oxygen, and zinc.

rashleighite
A ferrian variety of turquoise.

raslakite
A trigonal-ditrigonal pyramidal brownish red mineral containing calcium, chlorine, hydrogen, iron, niobium, oxygen, silicon, sodium, and zirconium.

rasorite
kernite

raspite
A monoclinic-prismatic mineral containing lead, oxygen, and tungsten.

rastsvetaevite
A trigonal-ditrigonal pyramidal pink mineral containing calcium, chlorine, hydrogen, iron, oxygen, potassium, silicon, sodium, and zirconium.

rasvumite
An orthorhombic-dipyramidal mineral containing iron, potassium, and sulfur.

rathite
A monoclinic-prismatic lead gray mineral containing arsenic, lead, silver, sulfur, and thallium.

rationalsphere
An online community of individuals, centered around the forum LessWrong and the blog Slate Star Codex, who discuss philosophy, psychology, and futurism through the lens of Bayesianism and rationality.

rauchite
A triclinic yellowish-green mineral containing astatine, hydrogen, nickel, uranium, and oxygen.

rauenthalite
A triclinic-pinacoidal mineral containing arsenic, calcium, hydrogen, and oxygen.

rauvite
An amorphous mineral containing calcium, hydrogen, oxygen, uranium, and vanadium.

ravatite
A monoclinic-sphenoidal mineral containing carbon and hydrogen.

raygrantite
A colourless triclinic mineral containing lead, hydrogen, oxygen, zinc, silicon, and sulphur.

rayite
A monoclinic-prismatic mineral containing antimony, lead, silver, sulfur, and thallium.

rebulite
A monoclinic-prismatic dark gray mineral containing antimony, arsenic, sulfur, and thallium.

rectorite
A monoclinic mineral containing aluminum, calcium, hydrogen, oxygen, potassium, silicon, and sodium.

redcanyonite
A monoclinic yellow mineral containing nitrogen, hydrogen, oxygen, sulphur, uranium, and manganese.

reddingite
An orthorhombic-dipyramidal mineral containing hydrogen, manganese, oxygen, and phosphorus.

redgillite
A monoclinic-prismatic grass green mineral containing copper, hydrogen, oxygen, and sulfur.

redingtonite
A monoclinic mineral containing aluminum, chromium, hydrogen, iron, magnesium, nickel, oxygen, and sulfur.

redledgeite
A tetragonal-dipyramidal mineral containing barium, chromium, hydrogen, oxygen, and titanium.

redruthite
Synonym of chalcocite.

redruthites
plural of redruthite

reedmergnerite
A triclinic-pinacoidal mineral containing boron, oxygen, silicon, and sodium.

reevesite
A trigonal-hexagonal scalenohedral mineral containing carbon, hydrogen, iron, nickel, and oxygen.

refikite
An orthorhombic-disphenoidal white mineral containing carbon, hydrogen, and oxygen.

regur
A rich, black, loamy soil found in India.

regurs
plural of regur

reichenbachite
A dark green mineral containing copper, hydrogen, oxygen, and phosphorus.

reidite
A tetragonal-dipyramidal white mineral containing oxygen, silicon, and zirconium.

reinerite
An orthorhombic-dipyramidal mineral containing arsenic, oxygen, and zinc.

reinhardbraunsite
A monoclinic-prismatic light pink mineral containing calcium, fluorine, hydrogen, oxygen, and silicon.

renardite
A yellow orthorhombic mineral containing lead, hydrogen, uranium, phosphorus, and oxygen.

rengeite
A monoclinic-prismatic dark greenish brown mineral containing calcium, lanthanum, cerium, praseodymium, neodymium, samarium, oxygen, silicon, strontium, titanium, and zirconium.

renierite
A tetragonal-scalenohedral orange brown mineral containing arsenic, copper, germanium, iron, sulfur, and zinc.

reppiaite
An orange red mineral containing arsenic, hydrogen, manganese, oxygen, and vanadium.

restite
The mineral material left when rocks are heated so much that granite is formed.

restites
plural of restite

retgersite
A tetragonal-trapezohedral dark green mineral containing hydrogen, nickel, oxygen, and sulfur.

retinalite
A translucent variety of serpentine of a honey-yellow to greenish-yellow colour, with a waxy resinous lustre.

retinalites
plural of retinalite

retinasphalt
Retinite.
A type of amber found in sediments in the Charente-Maritime area of France.

retinasphaltum
Alternative form of retinasphalt.

retinite
Any of various resins, similar in appearance to amber, associated with brown coal.

retinites
plural of retinite

retzian
A certain arseniate mineral.

revdite
A monoclinic-sphenoidal mineral containing hydrogen, oxygen, silicon, and sodium.

reyerite
A trigonal-rhombohedral mineral containing aluminum, calcium, hydrogen, oxygen, potassium, silicon, and sodium.

reynoldsite
A triclinic mineral containing chromium, manganese, oxygen, and lead.

rhaetizite
A variety of the mineral kyanite.

rheniite
A triclinic mineral containing sulphur and rhenium.

rhetizite
Alternative form of rhaetizite.

rhizolite
A type of tectite meteorite

rhizolites
plural of rhizolite

rhodarsenide
An orthorhombic brown mineral containing arsenic, palladium, and rhodium.

rhodesite
An orthorhombic-dipyramidal silky white mineral containing calcium, hydrogen, oxygen, potassium, silicon, and sodium.

rhodizite
A basic borate mineral of cesium, aluminum and beryllium

rhodizites
plural of rhodizite

rhodolite
A purplish-red garnet.

rhodostannite
A tetragonal-dipyramidal reddish gray mineral containing copper, iron, sulfur, and tin.

rhyolite
An igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture.

ribbeite
An orthorhombic-dipyramidal pink mineral containing hydrogen, magnesium, manganese, oxygen, and silicon.

richardsollyite
A grey-black monoclinic mineral containing astatine, lead, sulphur and thallium.

richellite
A tetragonal-pyramidal mineral containing calcium, hydrogen, iron, oxygen, and phosphorus.

richelsdorfite
A monoclinic-prismatic mineral containing antimony, arsenic, calcium, chlorine, copper, hydrogen, and oxygen.

richetite
A triclinic black mineral containing hydrogen, lead, oxygen, and uranium.

rickardite
An orthorhombic mineral containing copper and tellurium.

rickturnerite
A white or pale green orthorhombic mineral containing chlorine, magnesium, hydrogen, oxygen and lead.

ricolite
A stratified ornamental stone, a form of serpentine.

ricolites
plural of ricolite

rietveldite
A orthorhomic mineral containing iron, sulphur, hydrogen, oxygen, and uranium.

rilandite
A monoclinic black mineral containing aluminum, chromium, hydrogen, oxygen, and silicon.

rimkorolgite
A monoclinic-prismatic mineral containing barium, hydrogen, magnesium, oxygen, and phosphorus.

rimstone
A secondary mineral deposit, with a stone-wall-like appearance made up of calcite and other minerals, that builds up to create cave pools.

rimstones
plural of rimstone

ringes
plural of ringe

ringstone
A carved, contoured, donut-shaped stone object in early Indian art.
A gemstone for use in an ornamental ring.

ringstones
plural of ringstone

rinkite
A monoclinic-sphenoidal mineral containing calcium, cerium, fluorine, niobium, oxygen, silicon, sodium, and titanium.

rinkolite
Synonym of mosandrite.

rinmanite
A hexagonal-dihexagonal pyramidal mineral containing aluminum, antimony, hydrogen, iron, magnesium, manganese, oxygen, and zinc.

riomarinaite
A monoclinic-prismatic mineral containing bismuth, hydrogen, oxygen, and sulfur.

riotintoite
A colourless triclinic mineral containing aluminum, hydrogen, oxygen and sulphur.

rittingerite
xanthoconite

rittmannite
A monoclinic-prismatic light yellow mineral containing aluminum, hydrogen, iron, manganese, oxygen, and phosphorus.