Bock, 80, was found in his swimming pool. He was known to exercise there every morning before work.
The Dallas County Medical Examiner's Office said Bock did not drown, but died suddenly of heart complications.
Julie Abbey, chief financial officer of Henry Bock Co., said Bock was still very involved in the company, despite his age.
"He had a brilliant mind for business," Abbey said. "He still ordered all our diamonds."
"Harry was a wonderful husband and father and a legend in the diamond and jewelry industry," the company said in a statement. "He was a man who did not suffer fools gladly, but always held his family and friends very close."
"He is respected throughout the world for his knowledge and expertise," the statement continued. "He will be deeply missed by his employees, friends and family who love him."
Bock was the son of a Lithuanian-Jewish jeweler whose family was deported to Nazi concentration camps during World War II.
Bock's mother and two sisters died in the camps, but Bock and his father survived and moved to Dallas, where Bock had a surviving sister.
Bock's father started and ran a small diamond importing business that Bock inherited upon his father's death in 1968. In 1977, Bock launched what became the Bachendorf's retail jewelry chain in the Dallas area.
Funeral services will be held Wednesday at 10 a.m. at Tiferet Israel Congregation, located at 10909 Hillcrest Road in Dallas.
Friends and family are requesting donations to the Dallas Holocaust Museum in lieu of flowers.