Emerald Basics

The most commercially important variety of the mineral species Beryl, emerald is defined against other members of the specie for its display of saturated green color.   In order for a stone to be classified as emerald, the green must be a strong enough to give an immediate, unquestioned impression of the color.  If a stone is too light, it will be classified as a green beryl.  Although there’s a difference in opinion about what is “too light” one thing is clear:  when you see gorgeous, rich green color – you know it’s an emerald.
 Colombian emeralds derive their color from the presence of the element chromium in the stones’ chemical make-up.   Brazilian (and some African sourced) emeralds owe their color to the presence of vanadium.  Until 1963, stones that achieved their green from any element other than chromium were not considered emeralds. Although this view has changed and vanadium-colored stones are officially recognized as emeralds, people still associate emeralds primarily with Colombia.
Unique gemological conditions must be just right for fine gemstones to grow.  In Brazil and Africa, emeralds grow in rocks and are mined from the host materials that contributed to their development.  Colombian emeralds, however, grow under very different conditions.  In a process called hydrothermal growth, mineral rich fluids rose up from fault lines in the earth.  These fluids interacted with the sedimentary rocks that characterize Colombia’s geologic character and crystal emeralds grew.  The distinct growth environment of Colombia is another factor that contributes to the highly specific nature of Colombian emeralds.

 

OTHER MEMBERS OF THE BERYL FAMILY INCLUDE:

  • AQUAMARINE – A GREENISH-BLUE BERYL

  • HELIODOR – A YELLOW/GOLDEN BERYL

  • MORGANITE – A PINK BERYL

  • GOSHENITE – A COLORLESS BERYL

  • GREEN BERYL – A BERYL WITH GREEN COLOR NOT SATURATED ENOUGH TO BE CONSIDERED EMERALD

  • BIXBITE – AN EXTREMELY RARE RED BERYL.  FOUND ONLY IN UTAH, THIS STONE IS OFTEN REFERRED TO AS “RED EMERALD” IN THE RETAIL MARKET. BUT DON’T GET CONFUSED…EMERALDS ARE ALWAYS GREEN!

 

Emerald Sources

ALTHOUGH DEPOSITS OF EMERALDS ARE FOUND THROUGHOUT THE WORLD (INCLUDING NORTH CAROLINA, USA), THE NATIONS OF COLOMBIA, ZAMBIA, BRAZIL, AND ZIMBABWE SUPPLY MOST OF THE EMERALDS IN THE INTERNATIONAL MARKET.  EMERALD MINING EXISTS IN LIMITED PRODUCTION IN THE NATIONS OF PAKISTAN, AFGHANISTAN, AUSTRALIA, RUSSIA, AND EGYPT AS WELL – BUT POLITICAL PROBLEMS, ROUGH TERRAIN, AND/OR LOW YIELD MEANS INHIBITS THE DEVELOPMENT OF COMMERCIAL MINING.

THROUGHOUT HISTORY, COLOMBIA WAS THE PRIME SOURCE OF THE HIGHEST QUALITY/QUANTITY EMERALDS.  COLOMBIA PRODUCES A BROAD RANGE OF EMERALD QUALITIES, AND IT IS THE FINEST OF THESE STONES AGAINST WHICH ALL OTHERS ARE JUDGED.  THE TRADITIONAL COLOMBIAN MINES OF MUZO, CHIVOR, AND COSCUEZ ARE KNOWN FOR RICH, DEEPLY SATURATED, VIVID GREEN GEMS SYNONYMOUS WITH THE CHARACTERISTICS OF AN “IDEAL EMERALD”.
OF THE THREE COLOMBIAN MINES, MUZO IS RENOWNED AS THE SOURCE FOR EMERALDS OF THE FINEST PURE GREEN COLOR.  DISCOVERED BY THE SPANISH CONQUISTADORS IN 1558, THE MINE HAD SUPPLIED FINE STONES TO NATIVE MINERS FOR YEARS.  THE SPANISH DISCOVERY TRANSFORMED THE EMERALD MARKET – AS THOUSANDS UPON THOUSANDS OF CARATS OF EXTRAORDINARY MUZO STONES MADE THEIR WAY TO THE COURTS OF INDIA, EGYPT, PERSIA, AND THE OTTOMAN EMPIRE.  IN FACT, MANY OF INDIA’S LEGENDARY EMERALDS ATTRIBUTED TO THE MYTHICAL “OLD MINES” (IMPLYING INDIA) WERE COLOMBIAN STONES.  TODAY, THESE FAMOUS MINES CONTINUE TO PRODUCE BEAUTIFUL STONES – BUT ON A VERY LIMITED SCALE.  ANOTHER COLOMBIAN MINE - LA PITA - IS THE CURRENT HIGHEST VOLUME PRODUCER FOR THE NATION. 
 

EMERALDS WERE DISCOVERED IN ZAMBIA IN 1931.  ALTHOUGH THE COLOR HAS A SLIGHT BLUISH GREEN COMPONENT THAT IS A BIT REMINISCENT OF GOOD (BUT NOT GEM) COLOMBIAN STONES, THEY LACK THE VIVID SATURATION AND MEDIUM TONE OF FINE COLOMBIAN MATERIAL.

 BRAZILIAN STONES TEND TO BE LESS RICH IN COLOR THAN THE STONES OF COLOMBIA.  FINE CRYSTALS HAVE BEEN FOUND, BUT BRAZIL’S STONES ARE USUALLY LIGHT TO MEDIUM IN COLOR, HAVE A STRONGER BLUISH TINGE, AND ARE MOST OFTEN CLASSIFIED AS “COMMERCIAL-QUALITY” GOODS.
 

THE FORTH IMPORTANT SOURCE OF EMERALDS – ZIMBABWE – ARE KNOWN FOR HAVING A VIVID YELLOWISH GREEN TO GREEN HUE.  MANY ARE QUITE CLEAN – LACKING THE PROMINENCE OF THE COMMON CLARITY CHARACTERISTICS TYPICAL OF MOST EMERALDS.  UNFORTUNATELY, ZIMBABWEAN EMERALDS ARE NOT KNOWN FOR THEIR LARGE SIZE; MOST STONES ARE UNDER 1 CT. IN WEIGHT.

 

EMERALD QUALITY FACTORS

A VIBRANT EMERALD FROM COLOMBIA IS CONSIDERED THE STONE AGAINST WHICH ALL OTHER EMERALDS ARE JUDGED.  WHEN FACTORS OF WEIGHT, MAKE, AND CLARITY ARE EQUAL, IT IS AN EMERALD’S HUE, TONE, AND SATURATION OF COLOR WHICH DETERMINES ITS VALUE.  THE MOST DESIRABLE EMERALD COLORS ARE BLUISH GREEN TO GREEN – WITH STRONG TO VIVID SATURATION AND MEDIUM TO MEDIUM DARK TONE.  IN THE TRADE, THIS COLOR IS DESCRIBED AS “COLOMBIAN”, AS IT MOST GENERALLY CAN BE ATTRIBUTED TO SUCH GEMS FROM A VERY SPECIFIC PART OF THE WORLD.
MOST EMERALDS HAVE A MODERATE TO SIGNIFICANT AMOUNT OF CLARITY CHARACTERISTICS – MINERAL CRYSTALS, LIQUID INCLUSIONS THAT MAY BE FILLED WITH GAS AND/OR CRYSTALS, GROWTH TUBES, AND FRACTURES.  THE MOST VISUALLY DISTINCTIVE EMERALD INCLUSIONS ARE A COLLECTION OF MOSSY-LOOKING FISSURES, AFFECTIONATELY DESCRIBED AS “JARDINS”.  WHILE ALMOST ALL EMERALDS HAVE SOME OR ALL OF THESE INCLUSIONS VISIBLE TO THE NAKED EYE, THE MOST VALUABLE EMERALDS WILL SHOW A MINIMAL AMOUNT OF SUCH CHARACTERISTICS.
LIKE ANY GEMSTONE, EMERALD’S VALUE INCREASES WITH SIZE.  A FINE STONE OF 3 CARATS OR MORE IN WEIGHT CAN EASILY COST FIVE TIMES MORE PER CARAT THAN A 1 CARAT STONE OF SIMILAR QUALITY.
WHEN CONSIDERING THE PURCHASE OF A GEM EMERALD, ASSURANCES OF ORIGIN AND TREATMENT ARE PARAMOUNT. COLOMBIAN ORIGIN IS THE MOST PRIZED PROVENANCE FOR EMERALD, AND SEVERAL WELL RESPECTED INTERNATIONAL LABORATORIES HAVE THE RIGHT EQUIPMENT TO PERFORM THE NECESSARY TESTS.  A GEMOLOGICAL REPORT WILL NOT INCREASE THE VALUE OF A GEM, BUT IT WILL PROVIDE PEACE OF MIND TO BOTH BUYER AND SELLER THAT THEIR STONE IS PROPERLY REPRESENTED.

 

Emerald Wear And Care

EVERYTHING VALUABLE – FROM FINE CLOTHES TO A LUXURY CAR – DESERVES SPECIAL CARE TO KEEP IT IN OPTIMAL CONDITION.  A FINE EMERALD IS NO EXCEPTION.  ALTHOUGH THEY HAVE A RELATIVELY HIGH LEVEL OF HARDNESS ON THE MOHS SCALE (BETWEEN 7.5 – 8) EMERALDS ARE DELICATE AND NEED TO BE WORN AND MAINTAINED WITH A GENTLE HAND.
MOST EMERALDS ARE MODERATELY INCLUDED.  THE NATURE OF SOME OF THESE CLARITY CHARACTERISTICS RENDERS AN EMERALD SOMEWHAT MORE DELICATE THAN OTHER STONES.  GEMS SET INTO PENDANTS, EARRINGS, AND BROOCHES ARE SUBJECT TO MINIMAL WEAR AND TEAR ARE USUALLY SAFE FOR EVERY DAY.  IN BRACELETS AND RINGS, WHERE THEY ARE MORE SUSCEPTIBLE TO “KNOCKS AND PINGS”, THEY SHOULD BE WORN JUDICIOUSLY: IF A ROUGH ACTIVITY IS PLANNED, IT IS WISE TO SET YOUR PRECIOUS EMERALD ASIDE FOR ANOTHER DAY.
MOST EMERALDS ARE TREATED WITH A NATURAL OIL TO IMPROVE THEIR APPEARANCE.  IT IS A NORMAL AND ACCEPTED PRACTICE THROUGHOUT THE TRADE.  TREATMENTS ARE NOT PERMANENT, AND MAY BE COMPROMISED WITH COMMERCIAL CLEANING METHODS AND/OR PRODUCTS.  THE BEST WAY TO CLEAN AN EMERALD IS TO WIPE IT WITH A SOFT CLOTH OR CHAMOIS.  IF YOUR JEWELRY IS VERY SOILED, A GENTLE CLEANING SOLUTION AND A DELICATE MASSAGE WITH A VERY SOFT BRUSH CAN BE USED.  THIS IS BEST HANDLED BY A JEWELRY PROFESSIONAL FAMILIAR WITH THE CARE AND HANDLING OF EMERALDS.
WITH PROPER WEAR AND CARE, AN EMERALD CAN PROVIDE GENERATIONS OF ENJOYMENT.