Mariana Minerals
Manufacturing & IndustrialDirect Ashby career site

Administrative Assistant

Location
Houston, TX · On-site
Job type
Full-time
Level
Entry level
Experience
1+ year
Listed
31 days ago

Skills & highlights for this role

  • calendar management
  • travel booking
  • expense reporting
  • Microsoft Office

Also useful

  • expense management systems

The Role

We are seeking a highly organized and proactive Administrative Assistant to support day-to-day administrative operations at our Houston office. 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.

The Administrative Assistant will provide administrative 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.

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

On-Site & Office Support

  • Provide in-office support as needed
  • Coordinate office supplies, deliveries, and facilities-related requests
  • Assist with visitor management and on-site meeting logistics
  • Support internal events and team off-sites

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 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

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.

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!

Read the original posting

From Mariana Minerals's careers page, first listed on Rolev.ai on October 10, 2026. Rolev.ai is not the employer.

How Rolev.ai helps with this application

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Common questions

Where is the Administrative Assistant job at Mariana Minerals located?

This Administrative Assistant position at Mariana Minerals is located in Houston, TX (On-site). Always check Mariana Minerals's application page for specific state eligibility or relocation policies.

What qualifications are required for Administrative Assistant at Mariana Minerals?

For the Administrative Assistant role, Mariana Minerals highlights 1+ year of relevant experience; experience with calendar management, travel booking, expense reporting, Microsoft Office. Rolev.ai can score your existing resume against these requirements and show any skill gaps before you apply.

How do I apply for the Administrative Assistant position at Mariana Minerals?

This listing links directly to Mariana Minerals's Ashby application page. You can apply directly on Mariana Minerals's site, or use Rolev.ai to check your resume fit, generate a zero-hallucination tailored resume and cover letter for this posting, and autofill the Ashby application form in 1 click with the Rolev.ai Chrome extension. You always review the form and press Submit yourself.