# Relationship history for MSHA mine 3101928

Current hierarchy: **Imerys S A; Norsk Mineral AS → The Quartz Corp USA → Bear Creek Mica Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Zemex Corp → Bear Creek Mica Plant; 1950-01-01 to 2003-03-02; source msha-controller-operator-history
- **controller_controls_mine:** J M Huber Corp → Bear Creek Mica Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mitchell Mining & Mfg Company → Bear Creek Mica Plant; 1981-05-01 to 1983-06-08; source msha-controller-operator-history
- **controller_controls_mine:** Mitchell Mining & Mfg Company → Bear Creek Mica Plant; 1981-05-01 to 1983-06-08; source msha-controller-operator-history
- **controller_controls_operator:** Mitchell Mining & Mfg Company → Mitchell Mining & Mfg Company; 1981-05-01 to 1983-06-08; source msha-controller-operator-history
- **operator_operates_mine:** J M Huber Corp → Bear Creek Mica Plant; 1983-06-09 to 1993-07-14; source msha-controller-operator-history
- **controller_controls_operator:** J M Huber Corp → J M Huber Corp; 1983-06-09 to 1993-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Aspect Minerals Inc → Bear Creek Mica Plant; 1993-07-15 to 1998-01-22; source msha-controller-operator-history
- **controller_controls_mine:** Ron  Peele → Bear Creek Mica Plant; 1993-07-15 to 1998-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Ron  Peele → Aspect Minerals Inc; 1993-07-15 to 1998-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Zemex Mica Corporation → Bear Creek Mica Plant; 1998-01-23 to 2007-10-18; source msha-controller-operator-history
- **controller_controls_mine:** Zemex Corp → Bear Creek Mica Plant; 1998-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zemex Corp → Zemex Mica Corporation; 1998-01-23 to 2007-10-18; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Bear Creek Mica Plant; 2001-03-28 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Cementos Pacasmayo SSA → Bear Creek Mica Plant; 2003-03-03 to 2007-09-04; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Bear Creek Mica Plant; 2007-09-05 to 2011-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Feldspar Corporation → Bear Creek Mica Plant; 2007-10-19 to 2014-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Cementos Pacasmayo SSA → Feldspar Corporation; 2007-10-19 to 2007-09-04; source msha-controller-operator-history
- **controller_controls_operator:** Zemex Corp → Feldspar Corporation; 2007-10-19 to 2003-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Feldspar Corporation; 2007-10-19 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Norsk Mineral AS  et al → Bear Creek Mica Plant; 2011-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norsk Mineral AS  et al → Feldspar Corporation; 2011-04-01 to 2014-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A  et al → Feldspar Corporation; 2011-04-01 to 2014-07-31; source msha-controller-operator-history
- **operator_operates_mine:** The Quartz Corp USA → Bear Creek Mica Plant; 2014-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A  et al → The Quartz Corp USA; 2014-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norsk Mineral AS  et al → The Quartz Corp USA; 2014-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → The Quartz Corp USA; 2014-08-01 to 2011-03-31; source msha-controller-operator-history