Jewelry Appraisal Info


Caution

Please use care in cleaning your jewelry.

We cannot accept liability for any damage you may cause. Dirt may be holding some gems in place!

Clean in a small bowl, and check carefully for dislodged stones.

Gem Care Chart

See Caution in the left information box.

Alexandrite Generally stable to light, heat & chemicals. Do not boil. Sonic OK, ultrasonic with care (jewelers only). Jade (Jadeite & Nephrite) Often polished with wax finish. Other- wise, very tough. Avoid high heat, solvents, acids & strong light. Soak briefly in ammonia, brush & Water-Pik.
Amber Easily damaged by heat, pressure, and chemicals. Wipe or soak in soapy water. Do not ultrasonic. Kunzite (Spodumene) Do not boil or ultrasonic. Heat & strong light can change color. Soak in ammonia, rinse & brush. Avoid hydrofluoric acid.
Amethyst Avoid strong heat & abrupt temperature changes. Boiling & ultrasonic should be done with care not to "shock" stone. Soak in ammonia & brush. Lapis Lazuli Do not boil or ultrasonic. Often dyed. Avoid heat, solvents, acids, strong detergents. Clean gently with soapy water.
Andalusite Ultrasonic OK. Do not boil. Malachite Do not boil or ultrasonic. Avoid heat, solvents, acids. Clean gently with soapy water.
Apatite Heat & strong light can cause color to change or fade. Do not boil. No ultrasonic. Opal Very delicate & heat sensitive. Do not boil or ultrasonic. Avoid all solvents, acids, heat, abrasion. Brush with soapy water; brush accent gems.
Aquamarine (Beryl) Do not boil. Ultrasonic with caution: jewelers should check for inclusions. Sonic OK. Acids can cause damage, especially hydrofluoric. Soak in ammonia, brush. Brush accent gems & Water-Pik with warm, soapy water. Pearls Organic; avoid chemicals, hair spray, perfume, perspiration. Very soft. Do not boil or ultrasonic. Wipe with soft, damp cloth after wearing. Do not store in safe deposit box for long periods. Need light.
Beryl Generally stable. Avoid boiling and ultrasonic; sonic cleaning is OK. Peridot May fracture if heat-shocked. Do not ultrasonic. Boil with care. Damaged by acids. Soak in ammonia & brush clean.
Cat's Eye (Chrysoberyl) Strong heat (jewelers torch) may destroy color. Boiling and ultrasonic cleaning best done carefully, by jeweler. Soak in ammonia, brush, Water-Pik. Quartz Avoid strong heat & abrupt temperature changes. Boiling & ultrasonic should be done with care not to "shock" stone. Soak in ammonia & brush.
Citrine (Quartz) Avoid strong heat & abrupt temperature changes. Boiling & ultrasonic should be done with care not to "shock" stone. Soak in ammonia & brush. Ruby & Sapphire (Corundum) Boiling and ultrasonic generally safe. Soak in ammonia & brush. Water-Pik with hot, soapy water. May have glass-filled cavities that could be dislodged.
Coral Organic material, soft & often dyed. Do not boil, ultrasonic or use chemicals. Clean with soapy water. Brush accent stones & clean with Water-Pik. Spinel Boiling OK; avoid heat shock. Sonic cleaning OK; ultrasonic with care. Jewelers'torch may fade light colors. Soak, brush & Water-Pik.Do not boil or ultrasonic. Will fracture if shocked. Damaged by hydrofluoric & hydrochloric acids. Soak in ammonia & brush, Water-Pik accent stones.
Diamond Untreated diamonds OK to boil & ultra- sonic. Soak in ammonia, brush & Water-Pik. Fracture-filled diamonds must be treated with care. Jeweler's torch can remove fillings—let him know if you know your diamond is filled! Tanzanite (Zoisite) Do not boil or ultrasonic. Fractures if shocked. Soak in ammonia & brush; clean accent stones with Water-Pik.
Diopside Do not boil or ultrasonic; do not expose to hydrofluoric acid. Very heat-sensitive. Soak in ammonia, brush. Topaz Do not boil or ultrasonic. Fractures if shocked. Soak in ammonia & brush; clean accent stones with Water-Pik.
Emerald (Beryl) Use extreme care. Usually filled with oil or resins that might be removed with cleaning. (Fillings can be restored.) Do not boil or ultrasonic. Rinse, brush & Water-Pik with warm, soapy water. Turquoise Do not boil or ultrasonic. Attacked by acids. Cosmetics or perspiration may discolor stone. Many are dyed or "stabilized" with resins. Brush with ammonia, rinse & dry.
Garnet Gentle boiling OK if temperature "shock" avoided. Ultrasonic with care. Sonic OK. Jewelers- avoid hydrofluoric acid & torch. Soak in ammonia, brush. Zircon Do not boil; ultrasonic OK. High heat or strong light could change color. Easily abraded—handle with care. Soak in ammonia, brush & Water-Pik.
Iolite Gentle boiling & ultrasonic OK. Avoid thermal shock. Acids can damage. Soak in ammonia, brush, Water-Pik. NOTE: If in doubt, let the appraiser clean your jewelry. Remember that cleaning might loosen stones—check carefully.

San Diego Gemological Lab is an AGA Certified Laboratory. Thom Underwood maintains the highest jewelry appraiser credentials in these professional appraisal & gemological organizations.

  • American Society of Appraisers
  • National Association of Jewelry Appraisers
  • Gemmological Association of Great Britain

Our appraisals are performed in accordance with the high standards of the Uniform Standards of Professional Appraisal Practice (USPAP), the American Society of Appraisers, & the National Association of Jewelry Appraisers. More about jewelry appraisals...