Gemstone Enhancement and Care Chart

Abalone (shell)
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
Abalone (shell) 3 no treatment n/a n/a n/a Shell is very soft so be mindful of scratching. Avoid sudden temperature changes, heat, chemicals, and ultrasonic cheaners. In addition to above precautions: avoid perfumes and hairsprays.  
3 dyed to add color commonly good DYED
3 stabilized prevent porosity occasionally fair STB
3 coated to protect and improve stability commonly good CTD
Agate (quartz)
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
agate (quartz) 6.5 no treatment n/a n/a n/a Normal Care  
6.5 bleached to alter color commonly good to excellent BL
6.5 dyed n/a n/a n/a Avoid ultrasonics, heat, harsh cleaners DYED
Alexandrite (chrysoberyl)
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
alexandrite (chrysoberyl) 8.5 not known to be treated n/a n/a n/a Normal Care  
8.5 oiled to improve clarity occasionally good Avoid ultrasonics, heat, harsh cleaners O
alexandrite, synthetic 8.5 lab created n/a n/a n/a Normal Care  
Almandite Garnet
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
almandite garnet 7 - 7.5 not known to be treated n/a n/a n/a Normal Care  
Amazonite (microcline feldspar)
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
amazonite (microcline feldspar) 6.5 no treatment n/a n/a n/a Avoid hard wear, heat, chemicals and ultrasonic cleaners.  
6.5 heated to improve color occasionally very good HE
6.5 dyed to improve color occasionally very good DYED
6.5 impregnated with colorless wax or oil to improve overall appearance and luster occasionally good to fair IMP
6.5 impregnated with hardening agents or plastic to improve appearance and durability usually very good IMP
Amber/Copal
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
amber / copal yellow, golden brown 2 - 2.5 no treatment n/a n/a n/a Amber is very soft, so be mindful of scratching. Copal is very soft and less stable than amber when left untreated. Avoid abrasives, ultrasonic, solvents and heat. Avoid prolonged direct sunlight, avoid alcohol and perfumes. Requires gentle handling. Clean with soft damp cloth only.  
2 - 2.5 heated to create sun spangles to improve appearance, deepen color, add spangles frequently good to very good HE
2 - 2.5 heated to improve clarity and darken color frequently very good HE
2 - 2.5 dyed/stained to alter color rarely variable DYED
2 - 2.5 pressed to create color, clarify and make gem larger commonly very good PRS
amber / copal green 2 - 2.5 blacken bottom of cab to create green color face up occasionally excellent Amber is very soft, so be mindful of scratching. Copal is very soft and less stable than amber when left untreated. Avoid abrasives, ultrasonic, solvents and heat. Avoid prolonged direct sunlight, avoid alcohol and perfumes. Requires gentle handling. Clean with soft damp cloth only. BLKND
2 - 2.5 heat and pressure in an autoclave to create color and mature copals frequently excellent LPLT
2 - 2.5 dyed to create color frequently good to very good DYED
2 - 2.5 pressed and dyed to create color, and a larger gem frequently excellent PRS
amber / copal red 2 - 2.5 heated to create color frequently good to very good Amber is very soft, so be mindful of scratching. Copal is very soft and less stable than amber when left untreated. Avoid abrasives, ultrasonic, solvents and heat. Avoid prolonged direct sunlight, avoid alcohol and perfumes. Requires gentle handling. Clean with soft damp cloth only. HE
  dyed to create color frequently good to very good DYED
2 - 2.5 pressed and dyed to create color, and a larger gem frequently excellent PRS
amber / copal doublet - all colors 2 - 2.5 assembled to alter color occasionally good Amber is very soft, so be mindful of scratching. Copal is very soft and less stable than amber when left untreated. Avoid abrasives, ultrasonic, solvents and heat. Avoid prolonged direct sunlight, avoid alcohol and perfumes. Requires gentle handling. Clean with soft damp cloth only. AS
Amblygonite (montebrasite)
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
amblygonite (montebrasite) 5.5 - 6 no treatment n/a n/a n/a Gentle wear, can be brittle. Avoid high temperatures.  
amblygonite (montebrasite) blue, green, yellow 5.5 - 6 irradiated to alter color frequently good IRR
Amethyst
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
amethyst 7 no treatment n/a n/a n/a Normal Care  
7 heated to improve color commonly excellent HE
Ametrine
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
ametrine 7 no treatment n/a n/a n/a Normal Care  
7 heated to improve color occasionally excellent HE
Ammolite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
ammolite doublet 3.5 - 4 assembled to improve durability frequently fair to good Ammolite is very soft, so be mindful of scratching. Avoid abrasives, ultrasonic, solvents and heat. Requires gentle handling. AS
ammolite triplet 6 assembled glass top to improve durability frequently good Avoid abrasives, ultrasonic, solvents and heat. Requires gentle handling. AS
ammolite triplet 7 assembled quartz top to improve durability frequently good AS
ammonite (fossil) 3.5 - 4 no treatment n/a n/a n/a Normal care  
Andalusite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
andalusite 7 - 7.5 no treatment n/a n/a n/a Normal Care  
7 - 7.5 heated to improve color occasionally excellent HE
chiastolite 5 - 5.5 no treatment n/a n/a n/a Normal Care  
viridine 7 - 7.5 no treatment n/a n/a n/a Normal Care  
Andradite Garnet
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
andradite garnet 6.5 not known to be treated n/a n/a n/a Normal Care  
color change andradite garnet 6.5 no treatment n/a n/a n/a  
demantoid garnet (andradite) 6.5 no treatment n/a n/a n/a  
6.5 low temperature heat to improve color often excellent HE
rainbow andradite 6.5 no treatment n/a n/a n/a  
Apatite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
apatite
green
5 no treatment n/a n/a n/a Apatite is moderately soft, so be mindful of scratching. Avoid ultrasonic cleaners.  
apatite
blue
5 no treatment n/a n/a n/a  
apatite
blue and yellow
5 heated to improve color frequently good HE
5 irradiated to improve color occasionally good IRR
cat's-eye, apatite 5 no treatment n/a n/a n/a Apatite is moderately soft, so be mindful of scratching. Avoid ultrasonic cleaners.  
5 heated to improve color frequently good HE
Aquamarine (beryl)
aquamarine (beryl) 7.5 - 8 no treatment n/a n/a n/a Normal Care  
7.5 - 8 heated to improve color frequently excellent HE
Aragonite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
aragonite all colors 3.5 - 4 no treatment n/a n/a n/a Aragonite is very soft, so be mindful of scratching. It is easily attacked and dissolved by acids such as vinegar. Avoid abrasives, ultrasonic, solvents and heat. Aragonite is generally unsuitable for jewelry  
3.5 - 4 dyed to alter color sometimes fair to good DYED
3.5 - 4 waxed to improve finish and durability sometimes fair to good W
Aventurine (quartzite)
aventurine
(quartzite)
6.5 no treatment n/a n/a n/a Normal Care  
6.5 dyed to improve color commonly good to excellent Avoid abrasives, ultrasonic, solvents and heat. DYED
Axinite
axinite 6.5 - 7 no treatment n/a n/a n/a Normal gentle care, avoid sharp knocks to prevent cleavage.  
Azurite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
azurite 3.5 - 4 no treatment n/a n/a n/a Azurite is very soft, so be mindful of scratching. Avoid abrasives, ultrasonic, solvents and heat. Azurite is generally unsuitable for jewelry  
3.5 - 4 coated to improve appearance and durability occasionally fair to good CTD
3.5 - 4 filled with oil/resin and polymer to stabilize & improve appearance occasionally good O
azurite in granite 5 - 7 no treatment n/a n/a n/a Normal Care  
Azurmalachite
gemstone/types hardness enhancement method(s) purpose frequency stability/durability care and handling on-air code
azurmalachite 3.5 - 4 no treatment n/a n/a n/a Azurmalachite is very soft, so be mindful of scratching/breaking. Avoid abrasives, ultrasonic, solvents and heat.  
3.5 - 4 impregnated to improve appearance and durability rarely fair to good IMP
3.5 - 4 filled with oil/resin and polymer to improve appearance and durability rarely good O