Caring Gems

HARD AS A ROCK?

One of the biggest factors to consider in the care of precious gems and metals is their hardness, which reflects their durability. To measure hardness, the jewelry industry uses the Mohs Scale. This gem-trade standard, conceived by Friedrich Mohs in the early 1800s, measures the ability of a gem or mineral to resist abrasion damage. Diamond is placed as the hardest substance at 10, while talc is considered the softest at 1. Rubies and sapphires rate at 9, topaz and spinel at 8 and quartz material (such as amethyst and citrine) at 7.

Most of the objects you and your jewelry come in contact with are either quartz-based or near quartz's hardness. If your gems are harder than Mohs 7, they will not be scratched; if they are softer, they could get damaged. And, believe it or not, the precious metals your gems are set in (platinum, gold and silver) fall below Mohs 4.5.

Rings and bracelets are most vulnerable to the realities of daily wear. But earrings and necklaces, even brooches, are also subject to chemical exposure, particularly if worn while cosmetics, perfume and hairspray are applied.

In addition to regarding how you wear and store your gemstone jewelry, you should consider how you clean it. Choose chemicals, brushes and techniques for the softest, most vulnerable gems in a piece. Although the precious metals used in jewelry are softer than most gems, it does not mean that cleaners tailored to a specific metal will not damage gems of a higher Mohs. For example, silver polish works fine for sterling alone, but can ruin porous gems (like opal, pearl, coral, lapis, turquoise, and amber) set in it. Ammonia is a particular threat to fragile gems. If you must use strong commercial products, and you can't bear to remove that ring, make sure you are wearing protective gloves (which you should do anyway, to protect your skin!).

The best way to clean most of your gem-set jewelry is to use a mild soapy solution in warm water, a soft brush, and a soft cloth to pat dry.

Popular Gems and Cleaning Tips:

Alexandrite (Mohs 8.5)	Clean with soapy water, alcohol or commercial cleaning solutions. An ultrasonic cleaner or steamer is safe.
Amber (Mohs 2-2.5)	Use only warm soapy water, no brush. Pat dry. Do not use mechanical cleaners; avoid abrasives, chemicals and heat.
Aquamarine (Mohs 7.5-8)	Warm soapy water and a soft brush is your best bet.Mechanical cleaners are safe, but not on heavily included gems. Avoid most chemicals, heat and excessive cleaning.
Coral (Mohs 3.5-4)	Gently wipe clean with a soft, cool, damp cloth. Do not use a brush or mechanical cleaners. Avoid abrasives, chemicals and heat.
Diamond (Mohs 10)	Mechanical cleaners are safe, unless a stone has fractures or is fracture-filled. If that is the case, avoid heat and chemicals.Ammonia-based cleaners or mild solvents are fine. If using warm soapy water, rinse well and pat dry to avoid residue. Vodka is said to produce sparkling results.
Emerald (Mohs 7.5-8)	Clean with a soft, damp cloth, warm water and a soft brush. Do not use mechanical cleaners. Avoid chemicals and heat that dissolve oils used during cutting and processing to conceal inclusions. Although emerald is harder than quartz, its crystal structure makes it brittle. Have a jeweler re-oil your emerald every few years. Avoid impacts.
Garnet (Mohs 7-7.5)	Warm soapy water and a soft brush is perfect. An ultrasonic cleaner is safe for most garnets, except andradite (the best known variety is demantoid). Do not use a steamer.
Jade (Mohs 6.5-7)	Warm soapy water will do the trick. Mechanical cleaners are safe. Avoid contact with warm acids.
Lapis Lazuli (Mohs 5-6)	Use warm soapy water. Do not scrub or soak. Wipe with a soft cloth. Do not use mechanical cleaners and avoid chemicals.
Opal (Mohs 5-6.5)	Use a soft dry or damp cloth. Do not soak. Do not use mechanical cleaners. Avoid impacts, dry conditions, heat and chemicals.
Pearls (Mohs 2.5-4.5)	Wipe clean after each use with a soft, dry or damp cloth. Mild soapy water is fine. No mechanical cleaners, heat or chemicals.
Peridot (Mohs 6.5-7)	Warm soapy water and a soft brush is your best bet. Do not use an ultrasonic cleaner or steamer. Avoid contact with acids.
Quartz (amethyst, citrine & ametrine) (Mohs 7)	Warm soapy water is perfect. An ultrasonic cleaner is usually safe, but a steamer is risky. Avoid acids, intense heat, and prolonged bright light.
Ruby & Sapphire (Mohs 9)	Clean with soapy water or commercial solvent and brush. Mechanical cleaners are safe, except for heavily included gems.
Spinel (Mohs 8)	Give it the kind of care you would ruby and sapphire.
Tanzanite (Mohs 6-7)	Give it the same kind of care you would a peridot.
Topaz (Mohs 8)	Give it the same care you would an emerald. Although it is hard, it cleaves. A sudden temperature change or impact can cause a break.
Tourmaline (Mohs 7-7.5)	Warm soapy water and a soft brush is your best bet. Do not use mechanical cleaners.
Turquoise (Mohs 5-6)	Wipe with a soft damp cloth and dry. Do not soak or use mechanical cleaners. Avoid chemicals. Silver cleaners will cause discoloration.