| 1927-06-28 |
|
| 1927-06-28 |
|
| 1927-06-28 |
Established on June 30, Showa 2 (1927) |
| 1964-04-10 |
|
| 1964-04-10 |
|
| 1964-04-10 |
Started rock extraction, processing, and sales business on April 10, Showa 39 (1964), at 1 Tanasawa, Oaza, Rokkasho Village, Kamikita District, Aomori Prefecture |
| 1964-04-10 |
Established on April 10, Showa 39 (1964), with business activities including rock extraction, processing, and sales at 1 Tanasawa, Oaza, Rokkasho Village, Kamikita District, Aomori Prefecture |
| 2008-10-01 |
Established as a holding company for Sumitomo Coal Mining Co., Ltd. (currently Sumishi Materials Co., Ltd.) |
| 2008-10-01 |
Established as a holding company for Sumitomo Coal Mining Co., Ltd. (currently Sumishi Materials Co., Ltd.) on October 1, Heisei 20 (2008) |
| 2009-08-20 |
|
| 2009-08-20 |
Established Sumishi Holdings Co., Ltd. on August 20, Heisei 21 (2009) |
| 2009-08-20 |
Established a shareholder registry administrator at 1-7-14 Nishishimbashi, Minato-ku, Tokyo, on August 20, Heisei 21 (2009) |
| 2012-08-20 |
|
| 2012-10-01 |
Established as a holding company for Sumitomo Coal Mining Co., Ltd. (currently Sumishi Materials Co., Ltd.) |
| 2016-04-01 |
|
| 2016-04-01 |
|
| 2016-04-01 |
Started manufacturing, procurement, and sales of industrial synthetic diamonds on April 1, Heisei 28 (2016), at 579 Akabira, Akabira City, Hokkaido |
| 2016-04-01 |
Established on April 1, Heisei 28 (2016), with business activities including manufacturing, procurement, and sales of industrial synthetic diamonds at 579 Akabira, Akabira City, Hokkaido |
