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color index

(Encyclopedia)color index, in astronomy, difference in an object's brightness as recorded between any two well-defined bands of the electromagnetic spectrum by using optical filters of different colors. If blue and...

larkspur, in botany

(Encyclopedia)larkspur, any north temperate, Old World annual of the genus Consolida of the buttercup family. Consolida species were formerly classified in the genus Delphinium, which includes similar annual, bienn...

litmus

(Encyclopedia)litmus, organic dye usually used in the laboratory as an indicator of acidity or alkalinity (see acids and bases). Naturally pink in color, it turns blue in alkali solutions and red in acids. Commonly...

turquoise

(Encyclopedia)turquoise, hydrous phosphate of aluminum and copper, Al2(OH)3PO4·H2O+Cu, used as a gem. It occurs rarely in crystal form, but is usually cryptocrystalline. Turquoise is opaque and has a waxy luster; ...

Spectral Classes for Main Sequence Stars (table)

(Encyclopedia)Characteristics of Spectral Classes for Main Sequence Stars ...

beryl

(Encyclopedia)beryl bĕrˈĭl [key], mineral, a silicate of beryllium and aluminum, Be3Al2Si6O18, extremely hard, occurring in hexagonal crystals that may be of enormous size and are usually white, yellow, green, b...

Spode, Josiah, I

(Encyclopedia)Spode, Josiah, I, 1733–97, English potter. He founded a pottery firm in 1770 at Stoke-on-Trent in the Staffordshire pottery district. Creating many of his patterns after Japanese designs, he develop...

sulphur-bottom whale

(Encyclopedia)sulphur-bottom whale: see blue whale. ...

cupric sulfate

(Encyclopedia)cupric sulfate ko͞oˈprĭk sŭlˈfāt, kyo͞oˈ– [key] or copper (II) sulfate, chemical compound, CuSO4, taking the form of white rhombohedral crystals or amorphous powder. It decomposes at 650℃ ...

hyacinth, in botany

(Encyclopedia)hyacinth, any plant of the genus Hyacinthus, bulbous herbs of the family Liliaceae (lily family) native to the Mediterranean region and South Africa. The common, or Dutch, hyacinth of house and garden...