BLACK DIAMOND
At COREJEWELS, we use only the highest quality black diamonds from among those that symbolize an "untainted" existence. These are branded as [EXCEPTIONAL BLACK].
Corejewels Diamond Quality 001
EXCEPTIONAL BLACK
At COREJEWELS, we have established four appraisal criteria: color, cut, absence of scratches, and luster. We evaluate grades in three levels: [EXCEPTIONAL BLACK], [RARE BLACK], and [BLACK], and we carefully select and use only [EXCEPTIONAL BLACK], which represents the highest standard.
Corejewels Diamond quality 002
GEMレポート
A gemological report is a document that states the results of scientific testing to identify the type of stone. At COREJEWELS, we prove that our diamonds are genuine by including a gemological report issued by a specialized institution.
*Gemological reports are provided free of charge for diamonds 0.3 ct (0.2 ct for engagement rings only) and above, and for bead diamonds 5.0 ct and above.
WHITE DIAMOND
The white diamonds used by COREJEWELS not only meet high international 4C standards, but are also carefully selected for their inherent individuality and brilliance, which cannot be expressed by numerical values alone.
Corejewels Diamond Quality 001
4C
The international appraisal standards [4C] applied to diamonds consist of four items: weight = carat, polishing technique = cut, transparency = clarity, and color = color.
Corejewels Diamond quality 002
CARAT
Carat (ct) is a unit of measurement of diamond weight, and 1 carat = 0.2 grams.
Corejewels Diamond quality 003
CUT
Cut is the only factor determined by human skill, graded on polish, symmetry, and proportion to maximize a diamond's brilliance. COREJEWELS uses only top-grade diamonds with a cut grade of Triple Excellent, Excellent, or Very Good.
Corejewels Diamond Quality 004
CLARITY
Clarity refers to the transparency of a diamond, determined by the size, position, and number of surface blemishes and inclusions. At COREJEWELS, we use diamonds with extremely high clarity, ranging from "IF" (internally flawless) to "VS2" (very slightly included), where inclusions are difficult to find even with 10x magnification, let alone with the naked eye.
Corejewels Diamond Quality 005
COLOR
As a guide for diamond color, DEF means colorless, GHIJ means near colorless, KLM means faint yellow, N-R means very light yellow, and S-Z means light yellow. COREJEWELS uses classes [D] to [H].