5 - Treatments, Lab-Grown, Imitations, and Disclosure

Question 1

Treatment

Answer 1

Any human-controlled process outside of cutting or polishing that improves the appearance, durability, or value of a gem.

Question 2

Diamond Bourses

Answer 2

Where dealers meet to exchange goods.

Question 3

Disclosure

Answer 3

Clearly and accurately informing customers about the nature of the goods they buy.

Question 4

What are the ten types of gem treatments?

Answer 4

Bleaching
Cavity Filling
Colorless Impregnation
Dyeing
Fracture Filling
Heating
Irradiation
Lattice Diffusion
Sugar & smoke treatments
Surface modification

Question 5

Bleaching

Answer 5

A treatment that uses chemicals to lighten or remove color.

Question 6

Which two organic gems commonly undergo bleaching, and what bleach is commonly used?

Answer 6

Pearls and ivory, with hydrogen peroxide.

Question 7

What three gems are commonly bleached and what is used?

Answer 7

Tiger’s eye, jadeite, chalcedony, with diluted acid and chlorine bleach.

Question 8

How can bleaching be used to lighten inclusions?

Answer 8

Laser-drilling and stronger solvents.

Question 9

Cavity filling

Answer 9

Fills and seals voids to improve appearance and add weight.

Question 10

What kind of blemishes does cavity filling address?

Answer 10

Cavities, pits, and other depressions.

Question 11

What kind of fillers are typically used in cavity filling?

Answer 11

Glass, plastic, and shellac.

Question 12

In what four gems is cavity filling frequently seen?

Answer 12

Tourmaline, opal, ruby, sapphire.

Question 13

What aspect of durability and what aspect of appearance does cavity filling improve?

Answer 13

Durability - hardness; appearance - luster.

Question 14

Colorless impregnation

Answer 14

Filling of pores or other openings with melted wax, resin, polymer, or plastic to improve appearance and stability.

Question 15

What kind of materials are often used in colorless impregnation?

Answer 15

Wax, resin, polymer, and plastic.

Question 16

What are the benefits of colorless impregnation?

Answer 16

Can seal, protect, and improve luster.

Question 17

What two gems are commonly treated with colorless impregnation?

Answer 17

Turquoise, jadeite.

Question 18

Dyeing

Answer 18

Adds or affects color by making it more even or changing it.

Question 19

What is required before a gem can be dyed?

Answer 19

A gem must have a porous surface or fractures that reach the surface.

Question 20

Quench-crackling

Answer 20

When a gem is rapidly heated and cooled to produce surface fractures, in order to prepare for dyeing.

Question 21

What five gems are typically dyed?

Answer 21

Turquoise, cultured pearl, chalcedony, lapis lazuli, jadeite.

Question 22

How can rock crystal be treated to imitate gems?

Answer 22

Rock crystal can be quench-crackled.

Question 23

Fracture (fissure) filling

Answer 23

Using a filler to conceal fractures and improve the apparent clarity of a gem.

Question 24

What materials are used in fracture filling?

Answer 24

Plastic, glass, polymer resins, and oil (Canada balsam and palm oils).

Question 25

In what gem is fracture filling most common?

Answer 25

Emerald

Question 26

How is ruby typically fracture-filled?

Answer 26

Ruby in particular is treated with high-lead-content glass.

Question 27

Heat treatment

Answer 27

Exposing a gem to rising temperatures for the purpose of changing its appearance.

Question 28

Is heat treatment stable?

Answer 28

Yes, under normal wear.

Question 29

How can heat treatment affect a near-colorless corundum?

Answer 29

It gives a blue color.

Question 30

How can heat treatment affect a dark blue sapphire?

Answer 30

It can lighten or eliminate blue.

Question 31

How can heat treatment affect rubies?

Answer 31

It can remove the purplish hue that some rubies have.

Question 32

How can heat treatment affect amber?

Answer 32

It can oxidize it and sometimes remove bubbles.

Question 33

Give an example of how heat treatment can add helpful inclusions?

Answer 33

It can create asterism.

Question 34

What is the usual length of treatment and chemical used?

Answer 34

It varies based on the desired result.

Question 35

What three elements cause a blue color in lattice diffusion?

Answer 35

Iron, titanium, beryllium.

Question 36

What two elements cause a red color in lattice diffusion?

Answer 36

Chromium, beryllium.

Question 37

What element and process causes blue asterism with lattice diffusion?

Answer 37

Titanium dioxide and long cooling.

Question 38

What colors can beryllium induce in lattice diffusion?

Answer 38

Pinkish orange, yellow, red, blue.

Question 39

Sugar treatment

Answer 39

Soaking an opal in hot sugar solution and then in sulfuric acid to darken it and bring out play-of-color.

Question 40

Smoke treatment

Answer 40

Heating a wrapped, usually low-grade opal until smoke or ash penetrates the surface to darken it and bring out play-of-color.

Question 41

What two things do sugar and smoke treatments have in common?

Answer 41

They are both surface treatments, and they both work based on carbon entering the stone.

Question 42

Surface modification

Answer 42

Altering the appearance by applying backings, coatings, or coloring agents (i.e. paint.)

Question 43

Backing

Answer 43

Applied to the pavilion, usually silver/gold foil, fabric, paper, or colored feathers.

Question 44

Where are backings usually used?

Answer 44

Costume jewelry

Question 45

What are the five usual types of coatings?

Answer 45

Wax, varnish, plastic, ink, and metallic compounds.

Question 46

What type of coating improves the luster of turquoise, jadeite, lapis lazuli, and opal?

Answer 46

Wax

Question 47

What are four types of gemstones that sometimes take coatings other than wax?

Answer 47

Beryl, corundum, quartz, jadeite.

Question 48

What are the compounds used for coloring agents?

Answer 48

Paint, ink, nail polish.

Question 49

What was the initial use of lattice diffusion?

Answer 49

Originally used to create asterism in sapphires.

Question 50

What are some popularly treated gems? Try to name 10.

Answer 50

Amethyst Aquamarine Chalcedony Citrine Emerald Jade Lapis Lazuli Opal Pearl Ruby Sapphire Tanzanite Tiger's-eye Topaz Turquoise Zircon

Question 51

What is considered a permanent treatment?

Answer 51

Some heat treatments.

Question 52

How difficult is it to detect heat and irradiation?

Answer 52

Very.

Question 53

What light feature is a strong indication of treatment?

Answer 53

Extraordinary color.

Question 54

Describe irradiation's vulnerabilities.

Answer 54

Can fade quickly in light in any kind, can destabilize with heat.

Question 55

Describe dyeing's vulnerabilities.

Answer 55

Can fade in sun and burn in heat.

Question 56

Describe colorless impregnation's vulnerabilities.

Answer 56

Wax or oil can "sweat" in heat, oils can dry up, standard cleaning can remove treatment.

Question 57

Describe the vulnerabilities of bleaching.

Answer 57

Does not hold up against chemicals that stain, can include skin oils.

Question 58

Describe the vulnerabilities of surface treatments.

Answer 58

Standard cleaning can remove treatments, heat can vaporize them.

Question 59

What is a common disruptor of treatments?

Answer 59

Heat

Question 60

Flame fusion

Answer 60

Powdered chemicals are dropped through a high-temperature flame onto a rotation pedestal to produce a synthetic crystal.

Question 61

Who pioneered flame fusion?

Answer 61

Verneuil

Question 62

What is the most common and least expensive method of growing synthetic stones?

Answer 62

Flame fusion

Question 63

Pulling

Answer 63

The synthetic crystal is grown from a seed that is dipped in chemical melt, then pulled away as it gathers material.

Question 64

Flux growth

Answer 64

Nutrients dissolve in heated chemicals, then cool to form synthetic crystals.

Question 65

Hydrothermal growth

Answer 65

Nutrients dissolve in a water solution at high temperature and pressure, then cool to form synthetic crystals.

Question 66

How do new synthetic gemstone methods affect the market of natural gems?

Answer 66

It tends to increase interest in the natural gemstone.

Question 67

Imitation gem

Answer 67

Any material that looks like a natural gem and is used in its place.

Question 68

What are natural look-alikes?

Answer 68

Other natural gemstones of the same color (i.e. green garnet = emerald)

Question 69

What are lab-grown imitations?

Answer 69

Lab-grown gemstones that are not necessarily the same chemical composition and crystal structure (i.e. lab-grown spinel for birthstones)

Question 70

What are plastic imitations?

Answer 70

Thoroughly unconvincing plastic replicas.

Question 71

Assembled stones

Answer 71

Fusion of 2+ separate pieces of material for a single piece.

Question 72

Doublet

Answer 72

Two separate pieces of material fused or cemented together to become a single assembled stone.

Question 73

Triplet

Answer 73

A single assembled stone formed from three pieces of material fused or cemented, or from two pieces and a colored cement layer.

Question 74

Phenomenal imitations

Answer 74

Manmade processes that can imitate phenomena in non-gems (ex. Cat's-eye glass)

Question 75

Does the FTC care when you cry?

Answer 75

No

Question 76

When should you disclose treatments?

Answer 76

Always, along with the 4 Cs.