Gemstone Care

Gemstone Cleaning & Special Precautions

Gemstones must be clean to display their true brilliance, colour intensity, lustre and special optical effects.
Simply wiping the stone with a damp then dry cloth, is normally sufficient to revitalise gemstones to full effect.
But over time, dirt accumulates around recessed stones and intricate jewellery metalwork, especially at the back of settings. Chemical cleaners and ultrasonics are commonly used to effectively remove this dirt, but not all gemstones can tolerate these methods.

See below for the suitability of chemical cleaners and ultrasonics for each gemstone and a normal cleaning method that may be used.
Also take note of the Special Precautions necessary for protect your gemstone from colour degragation and physical damage.


Natural Gemstone
Variety

Species or Group
to which It belongs

Toughness
Chemical Cleaners

Ultrasonic
Cleaners

Normal Cleaning Method & Special Precautions

Alexandrite
Alexandrite

Chrysoberyl
Excellent
Yes
Yes
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Alexandrite is a hard durable stone and remains stable in heat and sunlight, no special care is required.

Amethyst
Amethyst

Crystalline Quartz
Good

Yes

No

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Avoid exposure to sunlight and strong artificial light to prevent the colour from fading.

Ametrine

Ametrine

Crystalline
Quartz

Good
Yes
No
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Avoid exposure to sunlight and strong artificial light to prevent the colour from fading.

Andalusite
Andalusite
e

Andalusite
Good
Yes
No

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Andalusite is heat sensitive, avoid high temperatures to prevent fractures.

Aquamarine
Aquamarine
Beryl
Fair
Yes
No
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Although heat-treated stones are normally stable and will not fade in sunlight, avoid prolonged exposure to intense sunlight and artificial light. Avoid sudden temperature change.
Chalcedony
Chalcedony

Microcrystalline
Quartz

Very good
No
No
Use a mild soap and water solution and dry quickly with an absorbant cloth.
Some varieties of chalcedony may be dyed; chemicals may remove the colour.
Golden Citrine
Citrine
Crystalline Quartz
Good
Yes
No
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Avoid exposure to strong light or prolonged sunlight to avoid colour change.

Diamond
Diamond

Diamond
Good

Yes

Unless coated

Yes

Unless
coated

All gemstone cleaning methods are ok for untreated diamonds that do not have large inclusions. High temperatures may remove material from Cavity Filled diamonds. When stones are coated to improve the colour, avoid chemicals, ultrasonics, steaming and boiling.
Although diamond is the hardest natural material, it has perfect cleavage and may chip if it strikes against a hard surface. Protect jewellery from physical blows, especially rings.
Emerald
Emerald
Beryl
Poor to good
No

No

To avoid sudden temperature change, use warm water only in a mild soap & water solution. Clean with a soft toothbrush. Avoid chemical cleaners, they may remove the oil from oiled stones, degrading the colour and making inclusions more visible. A professional is required to clean the stone effectively and re-apply the correct type of oil.

Garnet
Garnet

Garnet Group
Fair to good
Yes
No

Use a commercial jewellery cleaner or a mild soap & water solution and clean with a soft toothbrush.
Avoid cleaning products that contain hydrofluic acid.
Avoid sudden temperature changes to prevent fractures, through thermal shock.

Heliodor
Heliodor
Beryl
Fair
Yes
Yes
Use a commercial jewelery cleaner or use 'warm water only' in mild soap & water solution, to avoid thermal shock.
Avoid sunlight, treated stones can fade to their original paler colour.
Iolite

Iolite
Cordierite
Fair
Yes
Yes

Use a commercial jewellery cleaner or a mild soap & water solution and clean with a soft toothbrush..
Acids can damage iolite, check cleaning products for the inclusion of acids and avoid.

Jade
Jadeite & Nephrite
Jade
Excellent
No
No
Use a damp cloth then a dry absorbant cloth to dry quickly.
Jade is often dyed or filled, avoid the use of chemicals, soaking or steam cleaning.
Jade is very tough, precautions are mainly to avoid a colour change.
Kunzite
Kunzite
Spodumene
Poor
No
No

Use 'warm water only' in a mild soap & water solution. Clean with a soft tooth brush.
Protect from both heat and strong light to avoid the colour fading. Kunzite has perfect cleavage in two directions, so wear with care to avoid physical blows. Do not use hydrofluic acid products.

Lapis Lasuli
Lapis Lasuli
Lazurite
Fair
No
No
Clean with a damp lint free cloth. Lapis may be dyed or oiled and therefore may be affected by chemicals, soaking in solutions or steam cleaning., avoid all these methods.
Moonstone
Moonstone
Feldspar
Poor
Yes
No
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Moonstone is a soft stone with perfect cleavage, wear with care to avoid physical blows.
Morganite
Morganite
Beryl
Fair
Yes
No

Use a commercial jewellery cleaner or use 'warm water only' in a mild soap and water solution.
Avoid sudden temperature change to avoid thermal shock.

Opal
Opal
Opal
Poor
No
No
Use a dry or damp cloth to clean.
Do not soak in cleaning solutions.
Opal is affected by thermal shock, avoid heat and sudden temperature change.
Pearl

Pearl
Organic
poor
No
No

Use a damp cloth to remove the oils deposited from skin secretions, as they contain harmful acids.
Avoid contact with deoderants, perfumes and sun lotions.
Commercial pearl cleaning solutions are available.
Wear pearls with care to avoid physical damage.

Peridot
Peridot
Olivine
poor
No
No
Use a mild soap and water solution and clean with a soft toothbrush.
Avoid harsh chemicals, peridot is susceptible to acids includung those from skin secretions, perfumes etc.
Rhodolite
Rhodolite
Pyrope/Almandine
Garnet
Good
Yes
No

Use a commercial jewelery cleaner or 'warm water only' in a mild soap and water solution.
Also avoid sudden temperature changes to prevent thermal shock.
Avoid cleaning products that containn hydrofluic acid.

Rubellite
Rubellite
Tourmaline
(Red Tourmaline)
Good
Yes
No

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Avoid prolonged exposure to sunlight or strong artificial light as irradiated stones may fade to their original paler colour: high temperatures may also change the colour.
Avoid sudden temperature changes to prevent thermal shock.

Ruby
Ruby
Corundum
Excellent
Yes
Yes

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Be aware of surface filling treatments, they may be effected by chemicals and ultrasonics. Rubies are occationally oiled, if so, avoid chemicals and steam cleaning.

Sapphire
Sapphire
Corundum
Excellent
Yes
Yes

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Be aware of surface filling treatments, they may be effected by chemicals and ultrasonics (as with ruby).
Most teated sapphires are colour stable, except yellow and orange irradiated stones, they may fade in strong light.

Spinel
Spinel
Spinel
Good
Yes
Yes

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush.
Spinel is colour stable and is not normally colour enhanced.
It is a durable stone, not requiring any special care.

Tanzanite
Tanzanite
Zoisite
Poor
No
No

Use 'warm water only' in a mild soap and water solution to avoid thermal shock.
Also avoid sudden temperature changes in outside conditions.
Tanzanite has the appearance of a sapphire, but does not have the same durability. A perfect cleavage means avoiding physical knocks to prevent damage.

Topaz
Topaz
Topaz
Poor
No
No
Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft tooth brush.
Blue stones, from irradiated brown stones, are colour stable. Yellow and orange irradiated stones may fade in strong heat and light. Natural brown and irradiated green stones may fade in sunlight.
Topaz has perfect cleavage, avoid physical knocks to prevent damage.
Tourmaline
Tourmaline
All varieties
Good
Yes
No

Using commercial jewellery cleaners is ok. When using mild soap and water solutions use ' warm water only' as high temperatures may fade the colour of treated stones. Sudden temperature change may also induce thermal shock.
Avoid prolonged exposure to sunlight or strong artificial light as irradiated stones may fade to their original paler colour.

Turquoise
Turquoise
Turquoise
Good
No
No

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Turquoise is often treated with polymers to stabilise. Surface waxing is also done.
Natural stones are porous, so avoid using chemicals, soaking or steam cleaning.

Yellow Beryl
Yellow Beryl
Beryl
Fair
Yes
Yes

Use a commercial jewellery cleaner or use 'warm water only' in a mild soap solution to avoid thermal shock.
Avoid exposure to sunlight and strong artificial light, to prevent treated stones fading to their original paler colour.

Zircon
Zircon
Zircon
Fair to good
Yes
Yes

Use a commercial jewellery cleaner or a mild soap and water solution and clean with a soft toothbrush..
Avoid exposure to sunlight and strong artificial light, to avoid treated stones fading to their original paler colour.
Wear with care to avoid physical blows, the facet edges are brittle and subject to chipping.



More on cleaning methods


Chemical cleaners

Chemicals may remove dyes, oils and wax fillers from treated stones.
Porous stones may be stained by cleaning fluids.
Chlorine can discolour low carat gold by attacking the alloys within the metal.
The presence of acids in solutions will damage some stones.

Read the product instructions fully before using chemical cleaners.

Beware that some gemstones are Incorrectly Named. Tradenames may describe a 'different species of stone'

Ultrasonics
Ultrasonics use high frequency vibrations to shake loose the dirt lodged between metalwork and the gemstones.

Ultrasonics may damage some gemstones types. All heavily included gemstones are vulnerable to ultrasonics. Fracture filled and surface filled stones may lose their fillings.
Check with a jeweller for advice on your stone before proceeding. Positively identify your gemstones before using ultrasonics, as many stones look similar to others, but some types 'will be damaged' if this method of cleaning is used.
Before using a home ultrasonics device, have the stones identified and checked for inclusions or enhancements that may render this method of cleaning a risk. A jeweller or gemmologist will advise on this.

Steam cleaners
Steam cleaners can remove dyes, oils, wax fillers and other surface treatments. The heat from steam can also effect any stone that is prone to damage through thermal shock including 'heavily included stones'.
Boiling Boiling is used as a cleaning method, but few gemstones can tolerate this method, untreated diamonds are one of the exceptions.
Filled fractures may come loose, due to the difference in expansion between the gemstone and the filling material.
Soaking Porous stones can be stained if soaked in solutions. Dyed, oiled and wax filled stones may loose their colour and take on a pale or dull appearance..

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General Care of Gemstones

Caring for gemstones requires knowledge of each individual stone, what damages one stone may leave another unaffected.
Gemstones are made of chemicals and as such may be harmed by other chemicals.
Temperature extremes or sudden temperature changes may affect some, but not others.  
The severity of damage caused by accidental physical knocks varies throughout the gemstone range

Storage

Separate gemstones and jewellery pieces, by storing in sectioned boxes or wrap gemstones in paper. Otherwise damage may occur when harder stones contact softer stones, or when any stone contacts gold and other precious metalwork.

Do not lift or hold a jewellery piece by the stone or pull at the stone, it may losen in it's mounting and may eventually fall out.

Physical Damage During Wear

Be aware of the durability of the stone and the situations in which it can be worn (working environment). Durability is a combination of hardness, toughness and susceptibility to chemical erosion. All factors must be considered.

Remove rings before heavy work; otherwise the gemstone may loosen in the setting or be damaged.
Softer or brittle stones may suffer facet damage. When purchasing these stones, consider an emerald style cut; this cut was designed for better facet protection. The metalwork design may also provide extra protection for these gemstone types, especially when the stone is recessed.

Although diamonds are the hardest of all gems they possess perfect cleavage and may be chipped if struck against a hard surface.

Thermal Shock

Exposing gemstones from one extreme temperature to another, in a very short time, will cause 'Thermal Shock' in heat sensitive stones.

When wearing rings:

Avoid putting your hands in hot water or removing trays from the oven.
Do not put your hands over a hot vent when coming in from the cold (house heater or car vent etc).
In the above situations, sudden heat applied to an opal can quickly remove the water content and crack the stone.

Temperature Extremes

Some gemstones can tolerate extreme temperatures and are uneffected by the heat applied, during jewellery repairs.
It is advisable to positively identify a stone before any repair work is carried out. Mistaken identity may prove expensive.

Strong Heat & Light

The colour, or colour intensity, of some gemstones does not remain stable after heat-treatment or irradiation. The treatment may be affected by high temperatures, strong light or both. Some natural stones also fade under these conditions.

To avoid this happening, try not to wear jewellery at the beach, when in strong sunlight or when swimming.
If working under strong artificial light, shade the gemstone or remove the jewellery.  

Insure your jewellery

Keep your policies up-to-date and be aware of increases in market value.
Records of your jewellery should include photographs, weights, measurements and purchase information.

Be aware of enhancements

It is important to know if a gemstone has been treated to enhance its appearance. If unsure, check out the treatments that are typically applied to the gemstone in question, and take the appropriate precautions for those enhancements. See 'Gemstone Treatments' below.

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Gemstone Treatments


Most gemstones on the market today have been treated in some way. If they were'nt there would be few gemstones available on the market. Often the treatment finishes off what nature started, by applying the heat and/or radiation that was terminated pre-maturely during the stones natural creation.

An awareness of treatments is required to protect the enhancement from degradation. Applying the correct care method will ensure this.

Heat-treatment

This is the most common form of treatment carried out to enhance a gemstone. Heat treatment may change or intensify the colour and/or reduce the visibility of inclusions to improve the clarity. Some gemstones are heated to create inclusions to authenticate their appearance.

Following heat treatment, the colour remains stable in some gemstone types, but others may fade or revert to their original state. This may happen if they are subject to either strong artificial light or sunlight or high temperatures. Which of these factors affects the stone is again dependant of the gemstone type.

Stones subject to this treatment include: Some fancy coloured diamonds, sapphire, beryl, topaz, quartz and tourmaline.

Precautions: Avoid exposure to strong heat and/or light to any treated gemstone that is known to be suseptable.

Irradiation

Irradiation is also commonly used to enhance gemstones. Some stones are irradiated and then heat-treated,
This is the process used to produce blue topaz from brown topaz, the resulting colour remains stable in this case.

Some irradiated stones fade when exposed to strong light, this may happen in prolonged periods of sunlight or artificial light.

Stones subject to this treatment include: Diamond, sapphire, beryl, topaz, quartz and tourmaline. The stability of the treatment varies for each stone type.

Precautions: Avoid exposure to strong heat and/or light to any treated gemstone that is known to be suseptable.

Oiling

Oil is used to fill cracks that reach the surface of the gemstone, improving the clarity and colour of the stone. Reflections from cavity walls are no longer seen and colour beyond the cracks becomes visible. The oil may contain a dye to enhance the colour further: it is a common and accepted practice in some countries.
The oil eventually dries out and the stones appearance diminishes. Once this happens dirt may collect in cavities and be difficult to remove safely. A professional is then recommended to clean the stone and re-apply the correct oil.

Stones subject to this treatment include: Emeralds & rubies.

Precautions: For stones that may be oiled, check during purchase to see if the stone has in fact been oiled and, if acceptable, ask for details of the oil used. Re-oil occasionally to prevent the above problems. Periodic professional cleaning is advisable for expense stones.

Polymer and Resin Impregnation

Treatments are applied to increase the physical integrity and appearance of the gemstone by:

Stabilising porous gemstones through impregnation.
Repairing surface depressions of stones that undercut during cutting and polishing (pitted effect).
Filling cavities in cracked stones or laser drilled stones (glass is also used)
Some gem material is reconstituted and formed into stones by bonding crushed material in resins, turquoise is one example.

Gemstones subject to polymer and resin treatments include: Jade and natural turquoise.

Precautions: All polymer treated stones should avoid contact with solvents and should not be exposed to extreme temperatures.

Sugar Acid Treatments

Australian Andamooka matrix opal undergoes a sugar acid treatment to greatly enhance the opals play of colour. This is achieved by boiling the opal cabochon (already cut and polished) in a sugar and acid solution. This changes the opals normally light or white base colour to black. When seen against a black background, the opals ‘play of colour’ is intense, giving the treated stone a very attractive appearance.

Precautions: Beware of re-polishing these gemstones with abrasive wheels as the colour only applies to the surface of the stone to a depth of about one millimeter.

Surface Diffusion

Pale or near colourless gem material is 'Surface or Lattice Diffused' to apply a thin 'skin-deep' layer of colour. The finished stone appears as a fine example of the gemstone type.

Gemstones that may be diffused include: Sapphire and ruby.

Precautions: The surface colour of the stone will change if the stone is damaged or if re-polishing of facets is applied using abrasive wheels. Extra care is required to protect these stones. Some stones on the market sell at unexpectedly high prices, considering the nature of the enhancement.

Beryllium Diffused Sapphire and Rubies

Beryllium diffused corundum (sapphire and ruby) is new to the gem market. The process diffuses beryllium into corundum to create yellow, orange and brown colours from pale or nearly colourless material. It can also change the actual colour and transform dull coloured corundum into vibrantly rich coloured material. The diffusion may be close to the surface or may penetrate the entire stone. This is a very new treatment procedure and is still under scrutiny by professional gemmological associations.

 


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