quartz

---

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Species:  Quartz
​​Mohs Hardness:  7 out of 10
Color:  Occurs in many different colors.  Scroll below for a list of the different varieties of quartz.
RI:  1.544 to 1.553 (very constant)
Birefringence:  0.009
SR/DR/AGG:  DR
Clarity Type:  Type II
Optic Character:  Uniaxial positive.  Might show a bull's eye or Airy's spiral optic figure under crossed polarizing filters.
Pleochroism:  Weak to moderate, colors vary depending on variety of quartz.
Spectrum:  Not diagnostic
Fluorescence:  Generally inert
SG:  2.66 (+0.03/-0.02)

quartz facts

There are many different varieties of quartz, occurring in various colors.

Quartz crystals are used in electronics due to their ability to conduct electricity under pressure.

Quartz crystals allowed for battery operated watches, dating back to late 1969.

quartz varieties

amethyst

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

​Amethyst is the purple variety of quartz.​

ametrine

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Amethyst and citrine are the purple and orange varieties of quartz.

Ametrine is when quartz displays the colors of amethyst and citrine in a single gem.

aventurine

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Aventurine quartz is green due to many tiny, included green fuschite platelets.​
​Aventurine has a glitter effect caused by light reflecting off the fuschite platelets.

citrine

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

​Citrine is the yellow to orange variety of quartz.​

dendritic quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

​Rock crystal with dendritic inclusions that resemble tree branches.

Gold Bearing Quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Gold bearing quartz contains veins of pure gold.

prasiolite

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

​Prasiolite is the green variety of quartz.​​
Prasiolite is sometimes referred to as "green amethyst" or "lime citrine".

rock crystal

Photo courtesy of Mineral Miner's

​Rock crystal, also known as clear quartz, is the colorless variety of quartz.

rose quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

​Rose quartz is the pink variety of quartz.

rutilated quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Rutilated quartz is rock crystal quartz included with rods of rutile.

smoky quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Smoky quartz is the brown variety of quartz.

tiger's eye

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Tiger's eye quartz is a golden to red-brown color, with a phenomena known as "chatoyancy".

tourmalinated quartz

Photo courtesy of Scott Papper, GIA GG, AJP, Global Gemology & Appraisals

Tourmalinated quartz is rock crystal quartz with included tourmaline rods.