This stone dictionary will give you insight into the world of minerals, generally describing most of our utilized materials.

Stones by first letter: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Stones “R” Shown Below


Rainbow Moonstone – Rainbow Moonstone is not actually a Moonstone, but rather, a clear Labradorite which is Feldspar. When less inclusions are present, this translucent stone will shine blue, but with more inclusions, this stone portrays a rainbow of colors, hence its name.

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Rainbow Obsidian – Obsidian is a natural occurrence of volcanic glass. This Rainbow variety is created when gas bubbles from the lava flow are trapped as the flow cools and remain within the glass itself. The appearance is the black background with a rainbow sheen that reflects and shifts as the stone is moved in light.



Rainbow Schist – Schist is a metamorphic rock made up of layered minerals such as feldspar, mica and granite.



Rhodochrosite – Rhodochrosite is a Manganese Carbonate Mineral that displays banded patterns of pink, rose red and sometimes grey or yellow. Orbicular patterns can be found in the stalactite formations of Rhodocrosite, though it also grows and crystals, massive and botryoidal formations.



Rhodonite – The pearly silicate mineral known as Rhodonite is a rose pink color and often displays brown or black veins due to surface oxidation. First discovered in 1819, Rhodonite is found in many parts of the world; Canada, New Jersey, Brazil and several other regions. This pink stone is the state gemstone for Massachusetts.

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Rhyolite – Rhyolite is a volcanic mineral rock that can be made up of a variety of other minerals such as quartz, felspar and granite.



Roman Glass – Roman glass shards from the Roman Empire are most often from vessels, though some shards can be remnants of windows, and are found in varying vibrant colors including teal.



Rose Quartz – The generally pale pink variety of Quartz, which gets its color from inclusions of titanium, iron, manganese or dumortierite. Rose Quartz is photosensitive and can fade in color if left in the sun for an extended period of time.

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Ruby – Ruby is the red variety of corundum; any other color variety is Sapphire. Rubies are one of only four precious gemstones; Ruby, Sapphire, Emerald and Diamond. Rubies can range in red tones, from pink or orange reds to purple reds. In the USA, a corundum must be of at least a certain red saturation to be considered a Ruby, otherwise, it must be called a Pink Sapphire. Most Rubies are from Myanmar, though many other locales have been known to produce Rubies. Almost all Rubies are treated to enhance and improve clarity, color, transparency and inclusions.

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Ruby Zoisite – A Ruby-Zoisite is a mineral combination of non-transparent Ruby and Zoisite. This stone displays unique colorations of light green from the Zoisite portion with scattered red hues from the Ruby portion. This ornamental stone was first discovered in 1805 in Austria.



Rutilated Quartz – Rutile is a titanium dioxide mineral occurring in yellow gold, red, black or brown hues. These rutile needs, or crystals, can grow within quartz, creating striking patterns.

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Stones by first letter: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z