Gem by gem, from GIA
How to clean gemstones safely
Warm soapy water is safe for almost every gem. Ultrasonic and steam cleaners are not: they can crack, dull or damage many stones and treatments. Here is what GIA says for each birthstone.
| Gem | Warm soapy water | Ultrasonic cleaner | Steam cleaner |
|---|---|---|---|
| Garnet | Safe | Usually safe, except stones with fractures | Not recommended |
| Amethyst | Safe | Usually safe, except rare dyed or fracture filled stones | Not recommended (avoid heat) |
| Aquamarine | Safe | Usually safe, unless the stone has liquid inclusions or fractures | Usually safe, unless the stone has liquid inclusions or fractures |
| Bloodstone | Not covered | Not covered | Not covered |
| Diamond | Soak in water with a few drops of mild dish soap, then brush with a soft toothbrush | Use with caution; never for fracture filled diamonds; a jeweler should do it | Not covered in GIA's guide |
| Emerald | Safest method, with gentle scrubbing | Risky: vibrations can weaken stones with fractures | Risky: hot steam can force oil or resin out of fractures |
| Pearl | Safe for occasional cleaning | Never | Never |
| Alexandrite | Safe | Usually safe | Usually safe |
| Moonstone | The only recommended method | Never | Never |
| Ruby | Safe | Usually safe for untreated, heated and lattice diffusion treated stones; not for filled or dyed stones | Usually safe for untreated, heated and lattice diffusion treated stones; not for filled or dyed stones |
| Peridot | Safe (the best method) | Not recommended | Not recommended |
| Spinel | Safe | Usually safe (fractures can be a problem) | Usually safe (fractures can be a problem) |
| Sardonyx | Warm water, mild soap and a soft cloth or brush | Not covered by AGS | Not covered by AGS |
| Sapphire | Safe | Usually safe for untreated, heated and lattice diffusion treated stones; not for filled or dyed stones | Usually safe for untreated, heated and lattice diffusion treated stones; not for filled or dyed stones |
| Opal | The only safe method | Not safe (GIA: warm soapy water is the only safe way) | Not safe (GIA: warm soapy water is the only safe way) |
| Tourmaline | Safe (the best method) | Not recommended | Not recommended |
| Topaz | Safe (the best method) | Avoid | Avoid |
| Citrine | Safe | Usually safe, except rare dyed or fracture filled stones | Not recommended (avoid heat) |
| Turquoise | Safe | Never | Never |
| Tanzanite | Safe | Never | Never |
| Zircon | Safe (recommended) | Not recommended | Not recommended |
From each gem's GIA care and cleaning guide (AGS for sardonyx), linked on the gem's page. "Not covered" means our sources give no advice. Checked October 16, 2026.
The safe method for any gem
- Fill a bowl with warm (not hot) water and a few drops of mild dish soap.
- Soak for a few minutes, then brush gently with a soft toothbrush, especially behind the stone where grime collects.
- Rinse in clean warm water (close the sink drain first).
- Dry with a soft, lint-free cloth.
For pearls, skip the soak: GIA advises wiping them with a very soft cloth after each wear and only occasional washing.
Things to avoid
- Heat and sudden temperature changes: GIA warns they can crack amethyst, citrine, moonstone, opal, peridot, topaz, tourmaline and tanzanite.
- Chemicals: chlorine bleach and abrasive cleaners harm diamond settings; acids, perfume, hair spray and cosmetics damage pearls; lemon juice can damage fracture filled rubies and sapphires.
- Ultrasonic cleaners on treated stones: never use one on fracture filled emeralds, diamonds or other filled stones.
Frequently asked questions
Can I clean my gemstones with an ultrasonic cleaner?
Only some. GIA says ultrasonic cleaning is usually safe for untreated or heat treated ruby, sapphire, alexandrite, spinel, aquamarine and garnet, but never for pearl, opal, moonstone, turquoise or tanzanite, and not recommended for emerald, peridot, topaz, tourmaline and zircon.
How do I clean pearls?
Wipe them with a very soft cloth after each wear. For an occasional deeper clean, use warm soapy water and let strung pearls dry completely before wearing. Never use ultrasonic or steam cleaners.
Is toothpaste safe for cleaning jewelry?
No. GIA advises against abrasives such as toothpaste and household cleansers.