(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…
(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…
(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…
(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…
(Encyclopedia) berylberylbĕrˈĭl [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…
(Encyclopedia) Characteristics of Spectral Classes for Main Sequence Stars
Class
Color
Surface Temperature
Strong Lines
O
blue-white
35,000℃
ionized helium
B
blue-white
21,000℃
helium
A
white…
(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…
