Know what you are looking at.

Six things decide what a diamond costs and how it looks. Most of them are easier to understand than the trade makes them sound. Albert explains all of this in person too, but you may as well arrive knowing.

• Diamond Clarity

  Clarity describes what is inside a diamond and what sits on its surface. Almost every natural diamond has something. The question is never whether your stone has inclusions. It is whether you can see them.

• Diamond Carat

  Carat is weight. One carat is 200 milligrams, so a five carat stone weighs a single gram. The word comes from the carob seed, which the ancient trade used as a counterweight because the seeds were so consistent.

• Diamond Colour

  Colour grading measures the absence of colour. The scale runs from D, which is colourless, down to Z, by which point a warm tint is obvious. Most of what the scale measures, you cannot see.

• Diamond Cut

  Cut is not shape. Round, oval and pear are shapes. Cut is how well the stone was made: its proportions, its symmetry, and its polish. Of everything that determines whether a diamond looks alive, this is the one that matters most, and it is the one most people shop for last.

• Diamond Certification

  A grading report is an independent laboratory's description of one specific stone. It is not a valuation and it is not a guarantee of quality. It is a record, made by people with no stake in the sale.

• Diamond Shapes

  Shape is the outline of the stone, and it is usually the first thing someone knows they want. It also quietly changes the price, because shapes differ in how much rough diamond they waste.

• Conflict Free Diamonds

  The United Nations defines conflict diamonds as stones originating in areas controlled by forces opposed to legitimate governments, traded to fund military action against those governments. The trade usually calls them blood diamonds.