Minerals R - S

Red Quartz 

Location: Morocco, Brazil, Spain & more
This is quartz with hematite.
Variety of Quartz
Chemical Composition: SiO2 and Fe2O3
Hardness: 7

Rhodochrosite

(also called raspberry spar or manganese spar)
Location: Argentina, South Africa, Peru, Montana, Russia, China, Gabon, Mexico, Japan, & more
Chemical Composition: MnCO3, Manganese Carbonate
Hardness: 3.5 - 4

Rhodonite

Location: Madagascar, British Columbia, Russia, USA, Sweden
Chemical Composition: (Mn, Fe, Mg, Ca)SiO3 manganese silicate
Hardness: 5.5 - 6.5

Rose Quartz

Location: Brazil, Madagascar, USA, India & more
Light rose to a deep rose color
Variety of: Quartz
Chemical Composition: SiO2 
Hardness: 7

Ruby

Location: Afghanistan, Australia, Cambodia, India, Madagascar, Malawi, Mozambique, Pakistan, Sri Lanka, Tanzania, Thailand, the United States, Vietnam & more
Variety of: Corundum
Chemical Composition: Al2O3
Hardness: 9

Ruby-in-Zoisite 

Location: Zambia, Tanzania, India
Chemical Composition of Zoisite: Ca2Al3(SiO4)3(OH), Calcium Aluminum Silicate Hydroxide
Hardness: 6 - 7

Rutilated Quartz

Location: Australia, Brazil, Kazakhstan, Madagascar, Norway, Pakistan and the United States
Variety of: Quartz
Quartz chemical composition: SiO2 
Rutile chemical composition: TiO2 
Hardness: quartz 7, rutile 6 to 6.5

Sandstone
Location: Australia, United States, South Africa, Germany
Chemical Composition:  Quartz/ Feldspar Silicates
Hardness: 6-7

Sapphire

Location:  Australia, Afghanistan, Cambodia, Cameroon, China (Shandong), Colombia, Ethiopia, India (Kashmir), Kenya, Laos, Madagascar, Malawi, Mozambique, Myanmar (Burma), Nigeria, Rwanda, Sri Lanka, Tanzania, Thailand, United States (Montana) and Vietnam
Chemical Composition:  Al203
Variety of: Corundum or aluminum oxide
Hardness: 9

Selenite 

Location:  Worldwide, Mexico, Poland, Russia, Greece, Japan, Australia, Argentina, Brazil and the United States
"Selenite" is the colorless and transparent variety of gypsum that shows a pearl like luster and has been described as having a moon like glow. The word selenite comes from the Greek word for Moon and means moon rock.
Chemical Composition: CaSO4-2(H2O), Hydrated Calcium Sulfate
Hardness: 2 and can be scratched by a fingernail

Septarian 

Location: Utah, Madagascar 
Chemical Composition: CaCO3
The inside gold colored crystals are calcite and the brown banding is iron calcite. The outer surface was originally mud which, over millions of years, hardened into rock

Shungite

Location: Russia
Chemical Composition:  Carbon
Hardness: 3.5-4
A noncrystalline carbon with trace amounts of fullerenes

Smokey Quartz

Location: Brazil, Madagascar & more
Variety of: Quartz 
Chemical Compisition: SiO2
Hardness: 7

Stibnite 
Location: Hunan province, China; on the island of Shikoku, Japan; and in the western United States (Idaho, California, and Nevada)
Chemical Composition: Sb2S3, Antimony Sulfide
Hardness: 2

Sugilite

Location: Africa, Canada, Liguria and Tuscany, Italy; New South Wales, Australia and Madhya Pradesh, India.
Chemical Composition: KNa2Li3(Fe, Mn, Al)2Si12O30, Potassium Sodium Lithium Iron Manganese Aluminum Silicate
Hardness: 6 - 6.5

Sulfur

Location: Worldwide, Bolivia
Translucent resinous yellow
Chemical Composition: S , Elemental Sulfur
Hardness: 2