Industrial mineral site no. 1787, known as "Langell Deposit" is a site in San Juan County, Washington. This site has been associated with limestone and marble. A notation found in DGER Bulletin 52 on page 159-161 says "The limestone in this occurence is blue gray to white on fresh surfaces and weathers white. It is finely crystalline to dense in texture and contains argillaceous and cherty material", and designates the value as "Much of the limestone has a high silica content, and because of the small size of the occurence it is doubtful that much pure material could be obtained".