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olivine

(Encyclopedia)olivine ŏlĭvˈēn [key], an iron-magnesium silicate mineral, (Mg,Fe)2SiO4, crystallizing in the orthorhombic system. It is a common constituent of magnesium-rich, silica-poor igneous rocks; metamorp...

garnet

(Encyclopedia)garnet, name applied to a group of isomorphic minerals crystallizing in the cubic system. They are used chiefly as gems and as abrasives (as in garnet paper). The garnets are double silicates; one of ...

Equisetophyta

(Encyclopedia)Equisetophyta ĕkˌwəsətŏfˈətə [key], small division of the plant kingdom consisting of the plants commonly called horsetails and scouring rushes. Equisetum, the only living genus in this divisi...

bird of paradise

(Encyclopedia)bird of paradise, common name for any of 43 species of medium- to crow-sized passerine birds of New Guinea and the adjacent islands, known for the bright plumage, elongated tail feathers called wires,...

emerald flash

(Encyclopedia)emerald flash: see green flash. ...

cover crop

(Encyclopedia)cover crop, green temporary crop grown to prevent or reduce erosion and to improve the soil by building up its organic content. Green-manure crops, which are specifically grown for their organic conte...

chloroplast

(Encyclopedia)chloroplast klōrˈəplăstˌ, klôrˈ– [key], a complex, discrete green structure, or organelle, contained in the cytoplasm of plant cells. Chloroplasts are reponsible for the green color of almost...

ferrous sulfate

(Encyclopedia)ferrous sulfate or iron (II) sulfate, chemical compound, FeSO4. It is known as the monohydrate, FeSO4·H2O; the tetrahydrate, FeSO4·4H2O; the pentahydrate, FeSO4·5H2O; and the heptahydrate, FeSO4·7...

Herrera, Carmen

(Encyclopedia)Herrera, Carmen, 1915–, Cuban-American abstract painter, b. Havana. After studying architecture at the Univ. of Havana (1938–39), she trained at the Art Students League, New York (1942–43), then...

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...