The Collaborative International Dictionary of English v.0.48:

Almug \Al"mug\, Algum \Al"gum\, n. [Heb., perh. borrowed fr.
   Skr. valguka sandalwood.] (Script.)
   A tree or wood of the Bible (2 Chron. ii. 8; 1 K. x. 11).
   [1913 Webster]

   Note: Most writers at the present day follow Celsius, who
         takes it to be the red sandalwood of China and the
         Indian Archipelago. --W. Smith.
         [1913 Webster]

Easton's 1897 Bible Dictionary:

Almug
   (1 Kings 10:11, 12) = algum (2 Chr. 2:8; 9:10, 11), in the
   Hebrew occurring only in the plural _almuggim_ (indicating that
   the wood was brought in planks), the name of a wood brought from
   Ophir to be used in the building of the temple, and for other
   purposes. Some suppose it to have been the white sandal-wood of
   India, the Santalum album of botanists, a native of the
   mountainous parts of the Malabar coasts. It is a fragrant wood,
   and is used in China for incense in idol-worship. Others, with
   some probability, think that it was the Indian red sandal-wood,
   the pterocarpus santalinus, a heavy, fine-grained wood, the
   Sanscrit name of which is valguka. It is found on the Coromandel
   coast and in Ceylon.