Administrative Assistant
Mariana Minerals
Houston, TX · Posted October 27, 2026
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Where Houston, TX ranks
Where Houston, TX placed in our monthly rankings, month by month. Each month stays online at its own address.
November 2026
- #1Best cities for manufacturing and industrial jobs887 openings · of 100
- #1Best cities for energy and utilities jobs704 openings · of 27
- #1Cities hosting the most energy & utilities conferences11 conferences · of 15
- #2Cities with the most jobs that do not need a four-year degree in the Southwest481 jobs · of 38
- #2Best cities for software and engineering jobs in the Southwest1,018 openings · of 33
- #2Best all-round cities for mid-career professionals in the Southwest74 / 100 · of 15
Pay compared with the market
This listing does not state pay. Across 323 open administrative assistant listings that state pay, the middle half runs $41,500 to $59,000 and the median is $47,500.
Listed pay is what employers advertise, not what people are paid.
Administrative Assistant salaries by state · Check your own pay
How AI is used in this kind of work
Among secretaries and administrative assistants, except legal, medical, and executive, AI is already used for a large share of the tasks. Measured exposure for secretaries and administrative assistants, except legal, medical, and executive: 45% (high).
Share of this job’s tasks that AI is already used for at work, from real usage. It is not a forecast of job loss, and a low number means no use seen yet. Source: Anthropic Economic Index.
Skills this job asks for
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About the job
ABOUT MARIANA MINERALS
Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.
THE ROLE
The Administrative Assistant will provide administrative / executive support to the CFO, including calendar and travel coordination and expense management, while also supporting day-to-day office operations. The role will also serve as backup to the Executive Assistant as needed. This position requires strong communication skills, flexibility, sound judgment, and the ability to manage competing priorities in a fast-paced environment. This role is ideal for someone early in their career who is detail-oriented, resourceful, and eager to grow within an operations or executive support function.
WHAT YOU’LL DO
Administrative & Calendar Support
- Assist with scheduling meetings, managing calendars, and coordinating internal and external appointments
- Help prepare meeting materials, agendas, and notes as needed
- Support coordination of cross-functional meetings and company events
Travel & Logistics
- Book and manage domestic and international travel (flights, hotels, ground transportation)
- Handle last-minute travel changes and troubleshoot logistical issues
Expense & Reporting Support
- Prepare and submit expense reports in a timely and accurate manner
- Reconcile receipts and assist with tracking budgets or spending reports
Executive Assistant Backup
- Serve as backup to the Executive Assistant during absences
- Provide overflow support during high-volume periods
- Assist with special projects and ad hoc requests
DESIRED QUALIFICATIONS
- 1–3+ years of administrative / executive or office support experience preferred
- Strong organizational skills and attention to detail
- Excellent written and verbal communication skills
- Proficiency in Microsoft Office
- Experience with expense management and calendar systems preferred
- Ability to handle confidential information with discretion
- Strong time management and prioritization skills
- Problem-solving mindset
- Professional and service-oriented approach
- Adaptability in a fast-paced environment
- Team player with a positive attitude
OUR CULTURE IS BUILT ON FOUR PRINCIPLES:
Everyone Gets Home Safe. We never put speed or cost ahead of people.
Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.
Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.
Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.
Join us as we build the future of responsible mineral sourcing and supply!