January: Garnet
    
     Once available primarily as dark, reddish brown stones, 
     the gem marketplace now offers beautiful garnets in every 
     color, except blue. From bright green drusy Uvarovite, to 
     neon orange mandarin Spessartites, to pure spectral 
     green Tsavorites and raspberry pink rhodolites, garnets 
     are available in a wide price range and many cutting 
     styles. 
    
     Hardness ranges from 6.5 to 7.5, depending on the 
     species, garnets are reasonably durable gemstones for 
     most jewelry uses. 
    
     Main sources include India, Madagascar, Russia, Australia, 
     Sri Lanka and the USA. 
    
     As there no gem treatments commonly used on garnet to 
     enhance its color or other properties, it generally is safe to 
     assume the stones are natural. 
   February: Amethyst
   
    Long a favorite, purple quartz, or amethyst, is 
    available in sizes from small to huge, and in colors 
    from pale lilac "Rose d' France" to strongly saturated 
    "Siberian" purple with glints of red and/or blue. 
   
    As well as faceted stones, it is possible to find lovely 
    amethyst cabochons, carvings and beads. It is a 
    durable gem (hardness = 7) for most jewelry uses. 
   
    Brazil, Uruguay and Zambia are major sources in 
    today's market. 
   
    Most amethyst is heated to enhance its color, unless 
    stated otherwise, you should assume stones have been 
    treated. The heat induced color change is stable.
   March: Aquamarine
   
    Named for its resemblance to the color of sea 
    water, beryl in hues of blue-green to blue in 
    medium dark to pale tones is called aquamarine. 
   
    It can be found in a variety of cutting styles and 
    makes a brilliant and durable jewelry stone 
    (hardness = 7.5). 
   
    Virtually all aquamarine has been heated to 
    reduce green tones and produce a purer blue, a 
    change which is stable. 
   
    Main sources are Brazil, Zambia, Madagascar 
    and Nigeria.
  April: Diamond
  
   With hardness of 10 and the brightest luster 
   of all transparent gemstones, diamonds have 
   a unique place in the gem marketplace. 
  
   Diamonds occur in colorless and near 
   colorless forms as well as rare fancy colors. 
  
   Both color enhanced and synthetic diamonds 
   are available as well as many diamond 
   simulants, chief among them being cubic 
   zirconia. 
  
   Major sources include South Africa and 
   Australia. 
   May: Emerald
   
    Beryl with medium to medium dark green color, 
    contributed by chromium or vanadium content, is 
    called emerald. 
   
    Although frequently visibly included, traditional 
    oiling treatments enhance the clarity of most pieces. 
   
    With hardness of 7.5 they make reasonably durable 
    gemstones, oiled stones, however, require gentle 
    cleaning with no solvents, steam or ultrasonic. 
   
    The world's highest quality gems come from 
    Colombia but Brazil, Zambia and Russia also 
    contribute stones to the marketplace.