HEULANDITE  , a See also:

• MINERAL

mineral of the zeolite See also:

• GROUP

group, consisting of hydrous See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium and See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium silicate, H4CaAl2(SiO3)s + 3H20 . Small amounts of See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium and See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium are usually See also:

• PRESENT

present replacing See also:

• PART

part of the calcium . Crystals are See also:

• MONOCLINIC

monoclinic, and have a characteristic See also:

• COFFIN (from Lat. cophinus, Gr. K64wos, a coffer, chest or basket, but never meaning " coffin " in its present sense)

coffin-shaped See also:

• HABIT (through the French from Lat. habitus, from habere, to have, hold, or, in a reflective sense, to be in a certain condition; in many of the English senses the French use habitude, not habit)

habit . They have a perfect cleavage parallel to the See also:

• PLANE

plane of symmetry (M in the figure), on which the lustre is markedly pearly; on other faces the lustre is of the vitreous type . The mineral is usually colourless or See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white, sometimes See also:

• BRICK (derived according to some etymologists from the Teutonic bricke, a disk or plate; but more authoritatively, through the French brique, originally a " broken piece," applied especially to bread, and so to clay, from the Teutonic brikan, to break)

brick-red, and varies from transparent to translucent . The hardness is 31-4, and the specific gravity 2.2 . Heulandite closely resembles stilbite (q.v.) in See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance, and differs from it chemically only in containing rather less See also:

• WATER

water of See also:

• CRYSTALLIZATION

crystallization . The two minerals may, however, be readily dis- tinguished by the fact that in heulandite the acute See also:

• POSITIVE (or PORTABLE) ORGAN

positive See also:

• BISECTRIX (fem. of Lat. bisector, from bi-, two, secare, to cut)

bisectrix of the optic axes emerges perpendicular to the cleavage . Heulandite was first separated from stilbite by A . Breithaupt in 1818, and named by him euzeolite (meaning beautiful zeolite); independ- ently, in 1822, H . J . See also:

• BROOKE, FRANCES (1724-1789)
• BROOKE, FULKE OREVILLE, 1ST BARON (1554-1628)
• BROOKE, HENRY (c. 1703-1783)
• BROOKE, SIR JAMES (1803-1868)
• BROOKE, STOPFORD AUGUSTUS (1832– )

Brooke arrived at the same result, giving the name heulandite, after the mineral See also:

• COLLECTOR

collector, HenryHeuland .

Heulandite occurs with stilbite and other See also:

• ZEOLITES

zeolites in the amygdaloidal cavities of basaltic volcanic rocks, and occasion-ally in See also:

• GNEISS

gneiss and metalliferous See also:

• VEINS

veins . The best specimens are from the basalts of Berufjord, near Djupivogr, in See also:

• ICELAND (Dan. Island)

Iceland and the Faroe Islands, and the See also:

• DECCAN (Sans. Dakshina, " the South ")

Deccan traps of the See also:

• SAHYADRI

Sahyadri mountains near Bombay . Crystals of a brick-red See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour are from Campsie Fells in See also:

• STIRLINGSHIRE

Stirlingshire and the Fassathal in See also:

• TIROL (or TYROL 1)

Tirol . A variety known as beaumontite occurs as small yellow crystals on syenitic schist near See also:

• BALTIMORE
• BALTIMORE, GEORGE CALVERT, 1ST BARON (C. 1580—1632)

Baltimore in See also:

• MARYLAND

Maryland . Isomorphous with heulandite is the See also:

• STRONTIUM [Symbol Sr, atomic weight 87.62 (0=16)]

strontium and See also:

• BARIUM (symbol Ba, atomic weight 137'37 [0=16])

barium zeolite brewsterite, named after See also:

• SIR

Sir See also:

• DAVID
• DAVID (a Hebrew name meaning probably beloved 1)
• DAVID, FELICIEN (1810—1876)
• DAVID, GERARD [GHEERAERT DAVIT], (?=1523)
• DAVID, PIERRE JEAN (1789–1856)
• DAVID, ST (Dewi, Sant)

David See also:

• BREWSTER, SIR DAVID (1781–1868)
• BREWSTER, WILLIAM (c. 1566–1644)

Brewster . The greyish monoclinic crystals have the See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition See also:

• H4(Sr, Ba, Ca)Al2(SiOa)6+31420. H 4CaAl2(SiO3)

H4(Sr, Ba, Ca)Al2(SiOa)s+3H20, and are found in the See also:

• BASALT

basalt of the See also:

• GIANT (O.E. geant, through Fr. giant, O.Fr. gaiant, jaiant, jeant, med. pop. Lat. gagante—cf. Ital. gigante—by assimilation from gigantem, ace. of Lat. gigas, Gr. yiyas)

Giant's See also:

• CAUSEWAY

Causeway in Co . See also:

• ANTRIM
• ANTRIM, RANDAL MACDONNELL, 1ST EARL OF (d. 1636)
• ANTRIM, RANDAL MACDONNELL, 1ST MARQUESS OF (1609-1683)

Antrim, and with See also:

• HARMOTOME

harmotome in the See also:

• LEAD
• LEAD (pronounced iced)

lead mines at Strontian in See also:

• ARGYLLSHIRE

Argyllshire . (L . J .