260 EEPORT OF NATIONAL MUSEUM, 1899. 



A comparatively small proportion of the calc-spar as found is fit for 

 optical purposes. That on the immediate surface is, as a rule, lacking 

 in transparency. Many of the masses, owing presumabl}^ to the 

 development of incipient fractures along cleavage lines, show internal, 

 iridescent, rainbow hues, such are known locally as "litsteinar" 

 (lightstones). Others are penetrated by fine, tube-like cavities, either 

 empty or filled with cla}', and still others contain cavities, sometimes 

 sufficiently large to be visible to the unaided eye, filled with water and 

 a moving bubble. The most desirable material occurs in compara- 

 tively small masses imbedded in a red-gra}-^ ckij, filling the veinlike 

 interspaces in the bottom of the pit. The nontransparent variety, 

 always greatly in excess, occurs in cleavable masses and imperfectly 

 developed rhombohedral, sometimes 1 to 2 feet in diameter, associated 

 with stilbite. 



Calc-spar has been exported in small quantities from Iceland since 

 the middle of the seventeenth century, though the business was not 

 conducted with any degree of regularity before the middle of the 

 present century, prior to that time ever3^one taking what he liked 

 or could obtain, asking no one's permission. About the tune Bartholin 

 discovered the valuable optical properties of the mineral (in 1669), the 

 royal parliament under Frederick III granted the necessar^^ permission 

 for its extraction.^ It was not, however, until 1850 that systematic 

 work was begun, when a merchant by name of T. F. Thomsen, at 

 Seydisf jord, obtained permission of the owner of some three-fourths 

 the property (the pastor Th. Erlendsson) to work the same. The 

 quarried material was then transported on horseback to the North- 

 fjord, and thence to Seydisf jord by water. In 1851 the factor H. H. 

 Svendsen, from Eskif jord, leased the pastor's three-fourths right for 10 

 rigsdalers a year, and the remaining fourth, belonging to the Govern- 

 ment, for 5 rigsdalers. Svendsen worked the mine successfully up to 

 1862, when one Tullinius, at Eskif jord, purchased the pastor's three- 

 fourths and leased the Government's share for five years, paying there- 

 for the sum of 100 rigsdalers [about 111 or $15]. This lease was 

 renewed for four years longer at the rate of 5 rigsdalers per year 

 and for the year 1872 at the rate of 100 rigsdalers, when the entire 

 property passed into the hands of the Government in consideration of 

 the payment of 16,000 kroner [about $3,800]. From that time until 

 1882 the mine remained idle, when operations were once more renewed, 

 though not on an extensive scale, owing, presumably in part, to the 

 fact that Tullinius, the last year he rented the mine, had taken out a 

 sufficient quantity to meet all the needs of the market. Over 300 

 tons of the ordinary type of the spar is stated to have been sent to 

 England and sold to "factory owners" (Fabrikanter) at about 30 

 kroner a ton, though to what use it was put is not stated. 



1 Laws of Iceland, I, 1668, pp. 321, 322. 



