Erebaurerebaur.com/care-chart/
Gem care chart
Ultrasonic and steam safety, hardness and what each stone cannot take, for 25 gemstones. Following GIA care guidance.
Ultrasonic and steam
Our scheme, mapped from GIA's wording
Safe method (GIA)
Warm soapy water and a soft brush
No ultrasonic or steam
Emerald, opal, pearl, tanzanite, turquoise
Storage
Store jewels separately in soft pouches or divided boxes: diamond and corundum scratch softer gems and metals. Remove rings for heavy manual work and have prongs checked, since a worn setting can release a stone.
| Stone | Mohs | Ultrasonic | Steam | Notes |
|---|---|---|---|---|
| Diamond | 10 | Caution | Caution | GIA advises against ultrasonic and steam cleaners at home because vibration can loosen settings; jewelers inspect pieces first. |
| Ruby (untreated or heated) | 9 | Safe | Safe | Also safe for lattice-diffused stones. Boric acid powder etches even untreated corundum. |
| Ruby (glass-filled) | 9 | Avoid | Avoid | GIA: high-lead glass is altered by chemicals as mild as lemon juice, so fracture-filled, cavity-filled or dyed ruby takes a damp cloth only. |
| Sapphire (untreated or heated) | 9 | Safe | Safe | Fracture-filled, cavity-filled or dyed sapphires should be cleaned with a damp cloth only. |
| Alexandrite | 8.5 | Safe | Safe | GIA rates both usually safe; use only warm soapy water if fractures have been filled. |
| Spinel | 8 | Caution | Caution | Usually safe, but fractures can be a problem; rare fracture-filled stones need soapy water or a damp cloth. |
| Topaz | 8 | Avoid | Avoid | Basal cleavage makes it prone to splitting; sharp temperature changes can break it. Coated topaz needs gentle cleaning. |
| Emerald | 7.5–8 | Avoid | Avoid | Most emeralds are fracture-filled; vibration can worsen fractures and steam can draw out oils or resins. |
| Aquamarine | 7.5–8 | Caution | Caution | Usually safe unless the stone has liquid inclusions or fractures; rare fracture-filled stones need soapy water only. |
| Morganite | 7.5–8 | Caution | Caution | Usually safe unless the stone has liquid inclusions or fractures; avoid heat. |
| Tourmaline | 7–7.5 | Avoid | Avoid | High heat can change color and sudden temperature change can fracture it. |
| Amethyst | 7 | Caution | Avoid | Ultrasonic usually safe except for dyed or fracture-filled stones; sudden heat can fracture it. |
| Citrine | 7 | Caution | Avoid | Ultrasonic usually safe except for rare dyed or filled stones; GIA says citrine should not be heated. |
| Garnet | 6.5–7.5 | Caution | Avoid | Ultrasonic usually safe unless the stone is fractured; steam not recommended for any garnet. |
| Peridot | 6.5–7 | Avoid | Avoid | Rapid or uneven heat can fracture it; sulfuric acid and, over time, acidic perspiration attack it. |
| Kunzite | 6.5–7 | Avoid | Avoid | Perfect cleavage in two directions; color can fade with prolonged heat or intense light. |
| Jade (jadeite, nephrite) | 6–7 | Caution | Caution | Safe for untreated jade; dyed, bleached, impregnated or coated jade should get warm soapy water only. |
| Zircon | 6–7.5 | Avoid | Avoid | More brittle than sapphire; heat can alter color, and some heat-treated stones revert in bright light. |
| Tanzanite | 6–7 | Avoid | Avoid | GIA says never recommended; cleavage and fair to poor toughness, sensitive to sudden temperature change. |
| Moonstone | 6–6.5 | Avoid | Avoid | GIA says never recommended; two cleavage directions, and heat or sudden temperature change can break it. |
| Opal | 5–6.5 | Avoid | Avoid | Warm soapy water is the only safe method; heat or sudden temperature change can cause crazing or fractures. |
| Turquoise | 5–6 | Avoid | Avoid | Never steam or ultrasonic; heat and solvents damage treated surfaces, and skin oils and cosmetics discolor it. |
| Lapis lazuli | 5–6 | Avoid | Avoid | GIA's 4Cs cleaning guidance lists lapis among heat-sensitive stones not to be cleaned ultrasonically; warm soapy water, testing dyed stones first. |
| Pearl | 2.5 | Avoid | Avoid | GIA says never; acids in perfume, cosmetics and perspiration damage it. Wipe with a soft cloth after wearing. |
| Amber | 2–2.5 | Avoid | Avoid | GIA's 4Cs guidance says amber should not be put in an ultrasonic cleaner; warm water and mild soap only. Light darkens it and chemicals harm it. |