For other uses, see Zechariah. The male given name Zechariah is derived from the Hebrew ×Ö°×Ö·×¨Ö°×Ö¸×, meaning The Lord has remembered.. It has been translated into English in many variant forms and spellings, including Zachariah, Zacharias and Zachary. It was the name of various men in the Bible.
Double Refraction in Minerals Double refraction is the splitting of a single ray of light into two refracted rays when passing through an anisotropic mineral. All anisotropic minerals exhibit double refraction. Double refraction can be practically observed by placing a transparent Calcite (Iceland spar) crystal on a sheet of paper with a black dot on it. When the dot is viewed through the crystal, two dots are seen.
One ray (called the extraordinary ray) is bent, or refracted, at an angle as it travels through the medium; the other ray (called the ordinary ray) passes through the medium unchanged. 1  Double refraction can be observed by comparing two materials, glass and calcite.